Future send times and email backlog

Why are my send times so far out? Why aren't my emails being sent now?

There are a few reasons your send times can be scheduled in the future:

• Email is queued outside of sending hours: Unify emails will only be sent during your set sending hours. By default this is 9-4 PM PT, but you can further customize your daily send schedule in the email settings page here. More details can be found in this article. If you launch a play outside of these sending hours, those emails will get queued for the next available time. Let's say you launch a play that enrolls contacts in a sequence at 8 PM PT - the earliest possible time that email will get sent out is 9 AM PT the following day.

• Email skips sending on US holidays: By default, Unify will not send emails on US holidays. To change this setting, you can go into the email settings page here.

  

• Mailboxes may have a backlog of emails: Each mailbox will adhere to the 25 sends/day limit by default. If you have queued up more than 25 emails on a single mailbox, Unify will schedule these emails out across multiple days.

  • For example, let's say you queue 500 emails to be sent from one mailbox bob@tryunifygtm.com on Monday at 8 AM PT. These emails will take 7 days to go out and only be sent on business days. As an example, this is what the send schedule may look...

    • Monday: 25 emails

    • Tuesday: 25 emails

    • Wednesday: 25 emails

    • Thursday: 25 emails

    • Friday: 25 emails

    • Monday: 25 emails

    • Tuesday: 25 emails

    • Wednesday: 25 emails

  • Let's say during this period you queue an additional 100 emails to be sent from bob@tryunifygtm.com in a different sequence. The earliest available time those emails can be scheduled may be Wednesday or later the following week - Unify will need to go through the backlog of the previous emails you queued earlier before it send can those additional emails.

• Bulk enrollment eligibility checks may reduce enrolled contacts: When adding large contact lists to sequences, not all selected contacts will successfully enroll. The contact count shown in your play represents all contacts evaluated, while the sequence enrollment count shows only those who passed all eligibility checks—these numbers will typically differ. The system evaluates each contact against eligibility rules including re‑enrollment cooldowns, existing sequence enrollments, exclusion lists, mailbox sending limits, company caps, opted-out contacts, missing or invalid template variables, and persona or routing mismatches. This filtering is expected behavior and may result in fewer enrollments than the total contacts selected. To monitor enrollment progress and identify why specific contacts weren't enrolled:

• Navigate to the Play/Sequence and check Metrics > Enrollments > Not Enrolled (or Execution Logs) for the specific exclusion reason

• Open a sample contact's record and review the Exclusions section and Activity tab for notes like "already enrolled," "recently enrolled," or CRM‑exclusion details

• If you recently changed re‑enrollment rules or exclusions, wait 30‑60 minutes for changes to propagate before retrying

• If you just completed a bulk enrollment, enrollment counters may lag during eligibility checks. Wait 30‑60 minutes for the Not Enrolled list to fully populate with final results before troubleshooting further

• Contacts that pass eligibility checks but hit daily send limits will show as "Queued" and automatically continue as mailbox capacity becomes available

• Troubleshooting Exclusion-Related Drop-offs: If you notice a significant difference between your uploaded list size and actual enrollments, you can identify which specific exclusions are causing the drop-off by navigating to the play and toggling individual exclusions (such as "Customers" or "Open Opps") on and off. This will show you in real-time which contacts are being filtered out by each exclusion rule.

  More details on blocked enrollments can be found in this article.

  Re-enrollment After Exclusion Removal: Once a contact is removed from an exclusion list or no longer meets exclusion criteria, they can automatically be enrolled in plays again as soon as they meet the audience criteria and the audience is actively enrolling. This happens automatically on the next sync after the change. However, allow 15-45 minutes for exclusion changes to propagate before expecting new enrollments. Note that if the contact was previously enrolled in that specific sequence, you must enable “Allow re‑enrollment into the same sequence” in your sequence settings for them to enter it again. If they were never enrolled in that sequence before, the re‑enrollment setting is not needed—they’ll enroll automatically once exclusions no longer apply.

• Configuring Exclusions for Recently Contacted Contacts: To prevent enrolling contacts that were contacted within the last month, use an activity‑date filter such as “Last Activity Date is less than 1 month ago” in your exclusion rule.

  Critical Setting – “Exclude from Sequences” toggle: Keep this toggle OFF so matching contacts are blocked only from new enrollments while existing active enrollments remain unaffected. Switching it ON will also remove contacts from active sequences, which can disrupt ongoing outreach.

Unify automatically adds a 4–8 minute delay between individual emails to avoid sending them at the exact same scheduled times. This built‑in throttling makes sequences appear more natural and helps deliverability.

You can further randomize send times by using decimal values when setting delays between steps in your sequences. For example:

• Instead of exactly 2 days, use 2.04 days

• Instead of exactly 1 day, use 1.02 days

• Instead of exactly 3 days, use 2.97 days

When you set a delay between sequence steps (e.g., “1 day delay”), Unify counts the delay in calendar days, including weekends, but emails are only sent on business days. For example, if Email 1 is sent on Friday morning and Email 2 has a 1‑day delay, it becomes due on Saturday and will actually be queued for Monday morning within your send window.

How can I prevent an email backlog?

To mitigate backlog on a single mailbox, you can distribute your emails across multiple mailboxes. This can be done in the sequencing node of the play builder. You want to ensure you have enough mailboxes to support volume you'd like to send through Unify - you can estimate email volume by multiplying the # of sequence enrollments and # of email steps per sequence. As an example, let's say you want to send 1000 emails to all go out on the same week - you will need at least 4 mailboxes actively in the queue to get them all out in five business days.

Critical Configuration Rule: Each email address (mailbox) should only belong to one group to avoid conflicts and ensure predictable send scheduling.

Critical Mailbox Management Considerations for Email Scheduling

Mailbox Reassignment Risks

Mailbox Technical Constraints and Setup Requirements

• Each domain supports a maximum of 10 mailboxes

• Mailboxes connected to Unify must be exclusive to the platform and cannot be used with other email service providers simultaneously

• DNS records (SPF, DKIM, and MX) must be configured exclusively for Unify

• If you need more than 10 mailboxes for high‑volume sending, you'll need to set up additional domains

Critical Setup Step – Manual Mailbox Activation

1. Go to the sequence node in your play builder

2. Edit the routing settings

3. Explicitly select which mailboxes should be active for that sequence

When launching plays with large contact lists, Unify will display a warning if the volume would create a significant backlog based on your current mailbox capacity. If you receive a backlog warning, consider batching your contact list into smaller groups (e.g., 400 companies at a time) and launching them in intervals of a few weeks. This prevents creating a multi‑week backlog that would delay time‑sensitive signals like website intent or other triggered emails.

When planning for high‑volume email campaigns requiring more than 10 mailboxes, factor in the time and technical requirements for setting up additional domains with proper DNS configuration and mailbox provisioning.

Configuring Mailbox Routing for Sequence Distribution

While the article explains the importance of distributing emails across multiple mailboxes, you also need to configure the routing in each sequence.

1. In Play Builder, open the Sequence action and click Edit routing.

2. Add only the mailboxes you want to use for this sequence.

3. Remove those mailboxes from routing in any other sequences if you want them to be exclusive to this campaign.

When you select multiple mailboxes in the sequencing node, Unify automatically round‑robin distributes emails across those selected mailboxes, ensuring even distribution of email volume.

To separate mailboxes for different campaign types (e.g., warm vs. cold outbound), configure the routing settings in each sequence’s node to include only the dedicated mailboxes for that sequence type. This prevents cross‑contamination and maintains priority.

• Sequence Re-enrollment Limitations: Contacts enrolled in paused sequences cannot automatically move to other sequences. To prioritize urgent campaigns, you must manually remove contacts from their current sequences before they can be enrolled elsewhere.

Critical: Once manual emails are queued to send, reassigning the mailbox will cancel those queued emails and create entirely new enrollments. This forces you to re-queue manual emails with potentially much longer delays based on the new mailbox's backlog. Always finalize mailbox assignments before queuing manual emails.

Managing Backlogs Strategically

Understanding True vs. Inflated Backlog Numbers The "total emails in backlog" metric shown in the email backlog dashboard includes both queued emails and blocked emails. Blocked emails (due to missing template variables, exclusions, or other enrollment issues) don’t consume sending capacity and won’t affect your ability to launch new sequences. To see your true sending backlog, check the "Scheduled" count rather than the total backlog number.

Resolving Template Variable Blocks That Inflate Backlog If you have many blocked enrollments because of missing template variables (e.g., company name), refresh the template variables: right‑click individual enrollments and select “Refresh”, or use the bulk refresh feature to re‑evaluate and potentially queue emails for contacts with now‑populated data.

Key Point: Blocked Emails Don't Block New Sequences Blocked enrollments from existing sequences do not prevent new sequences from sending immediately. Even if your total backlog appears high, as long as the majority are blocked rather than queued, new sequence enrollments will send according to your available mailbox capacity.

Threaded Email Sequence Limitations: If you see a “step blocked” error for a contact even when all template variables are present, this may occur when the first email in a sequence (which acts as the thread root) was skipped for that enrollment. Since subsequent emails in the sequence are configured as replies in a thread, they cannot send without the initial email having been sent first.

1. Skip all remaining email tasks for that enrollment.

2. Unenroll and re‑enroll the contact so the sequence starts fresh from step 1.

3. Send one‑off emails outside of the sequence if you still need to reach that person.

For sequences that haven't had manual emails queued yet, you can reassign them to mailboxes with smaller backlogs to achieve earlier send times. Use the email backlog page to view current mailbox backlogs and make informed reassignment decisions.

Bulk Reassignment Options After Routing Changes

• Tasks: You can bulk reassign tasks by navigating to the Tasks tab, selecting all relevant tasks, and choosing "Assign Owner" from the bulk actions menu.

• Queued emails (Step 1 only): Emails that are queued but haven't been sent yet can be bulk reassigned via Dashboard > Leading > Email Backlog > Reassign Sequence Enrollments. Select the specific sequence and reassign the queued Step 1 emails. Important: This reassignment can only be done for queued enrollments that haven't sent yet - you cannot reassign enrollments that have already sent their first email. More details can be found in this article.

• Mid‑sequence scheduled emails: Emails that are already scheduled for steps beyond Step 1 cannot be bulk reassigned and must be updated manually on a per‑contact basis.

• Important limitation: Once Step 1 of a sequence has already sent, you cannot switch mailboxes mid‑sequence for those enrolled contacts, as this would create an inconsistent experience for recipients.

Tasks in sequences are assigned based on the sequence’s Advanced Settings for task assignment. If tasks are being assigned to the wrong person, check your sequence configuration:

1. Navigate to the sequence and click Edit

2. Go to Advanced Settings

3. Review the task assignment setting, which can be set to:

   • Mailbox owner (most common/recommended)

   • The person who manually enrolled the contact

   • Record owner

   • Manually assign tasks (allows routing future tasks to a specific user without changing mailbox ownership)

If the sequence is set to assign tasks to “the person who manually enrolled the contact” and someone other than the intended owner enrolled the contacts, this will cause tasks to be assigned to the wrong person.

To prevent future misassignments: Update the task assignment setting to “Mailbox owner,” “Record owner,” or enable “Manually assign tasks” to route to a specific user, as appropriate for your workflow. This will fix future tasks but won’t retroactively reassign existing ones—you’ll need to manually reassign those using the methods described above.

Important Limitation: Task ownership and mailbox ownership are independent—reassigning a task only changes the task assignee and does not change the mailbox used for any associated emails.

This means you can assign tasks (including call tasks, LinkedIn tasks, and other manual tasks) to one user while emails continue to send from the mailbox owner’s account.

Routing Future Sequence Tasks Without Changing Mailbox Ownership

To assign all future tasks from a sequence to a specific user while keeping emails sending from the current mailbox owner:

1. Open the sequence and click Edit

2. Navigate to Advanced Settings

3. Enable Manually assign tasks and select the desired task owner

4. Save the sequence

This configuration affects only new enrollments—existing enrollments retain their current task assignments. Emails will continue to send from the mailbox owner while tasks will be assigned to the specified user.

Understanding Simultaneous Launch Behavior

Sequences launched at the same time may send on different dates due to mailbox-specific backlogs. Each mailbox maintains its own queue, so sequences assigned to heavily backlogged mailboxes will send later than those on mailboxes with lighter loads.

Troubleshooting Confusing UI States

If emails show as "Queued" in Outbox > Scheduled but haven't actually been queued to send, this indicates manual email tasks are incomplete. You must complete these manual email tasks to actually queue the emails for sending - the "Queued" status in this case is misleading and doesn't reflect true queue status.

Monitoring for Stuck Sequence Enrollments

To identify contacts that are stuck in sequences without activity for extended periods, you can use two methods:

Method 1: Sequences Enrollments Page

1. Navigate to Sequences > [Select sequence] > Enrollments.

2. Filter by status (e.g., Active/Blocked).

3. Sort by Last activity to find older, inactive enrollments.

4. Review contacts with no recent activity and either skip their current task or unenroll them from the sequence.

Method 2: People Page

1. Go to the People page.

2. Filter for contacts who are in an active sequence.

3. Add a filter for contacts with no recent activity.

4. Review and take action on stalled enrollments.

Sequence Edit Limitations for Existing Enrollments

If you've edited a sequence to remove manual tasks or make other changes, but emails still aren't sending for contacts already enrolled, this is because sequence changes only apply to new enrollments. Once a contact completes step 1 of a sequence, they remain locked to that original sequence version and will not be upgraded to the edited version.

To resolve this issue when contacts are stuck on an outdated sequence version, duplicate the updated sequence and enroll contacts into the new sequence version. This will ensure they follow the current sequence configuration without being blocked by steps from the previous version that may no longer exist or have been modified.

Can I prioritize certain sequences over others?

Understanding Sequence Enrollment Rules and Re‑enrollment Configuration

By default, Unify prevents contacts from being enrolled in multiple sequences simultaneously. This restriction can be changed through the re‑enrollment settings.

• The simultaneous enrollment block is a default setting, not a hard system limitation.

• Re‑enrollment rules control both simultaneous enrollment and waiting periods between sequences.

• CRM‑based exclusions (e.g., HubSpot’s “currently in sequence” status) may still prevent enrollment even when simultaneous enrollment is enabled.

• Simultaneous enrollment: Allow contacts to be enrolled in multiple sequences at once (disabled by default).

• Same sequence waiting period: Minimum days between enrollments in the same sequence.

• Different sequence waiting period: Minimum days between enrollments in different sequences.

• Re‑enrollment permissions: Whether to allow re‑enrollment at all.

Troubleshooting Re-enrollment After Mailbox Changes:

If you need to re-enroll contacts after changing mailbox assignments:

1. Temporarily adjust re‑enrollment settings at Settings > Organization > Sequences > Rulesets to allow re‑enrollment with a 0‑day waiting period

2. Create an audience of the contacts you want to re‑enroll

3. Choose your enrollment approach:

   • Enroll them into the same sequence (they'll resume from their next step), or

   • Enroll them into a duplicate sequence if you want them to start from step 1

4. Revert the re‑enrollment settings to your preferred configuration after completing the re‑enrollment

Re-enrollment Behavior: When contacts are re‑enrolled in a sequence after being unenrolled (either manually or automatically), they resume at their next step in the sequence rather than starting from the beginning. If you need contacts to restart a sequence from step 1, you must enroll them in a duplicate of the sequence instead of re‑enrolling them in the original.

Paused vs. Completed Sequences: Contacts in paused sequences remain enrolled and will block new sequence enrollments. Pausing does not unenroll contacts; you must manually unenroll them or wait for sequence completion.

CRM Integration Impact: Even with simultaneous enrollment enabled, your CRM may enforce its own restrictions, such as HubSpot’s “currently in sequence” property.

1. Check active enrollments: Review sequence details pages to see if contacts are already enrolled elsewhere.

2. Verify re‑enrollment settings: Confirm your ruleset allows the type of enrollment you’re attempting.

3. Review CRM exclusions: Check for CRM‑based properties that might block enrollment.

4. Consider waiting periods: Ensure sufficient time has passed since previous enrollments based on your configured rules.

We will determine sending priority based on the time you launched the play that enrolls those contacts in a sequence. If you launch multiple plays on the same contacts, Unify will never enroll those contacts in multiple sequences at the same time. However, Unify will pick the play that launched first and enroll them in the appropriate sequence.

For urgent or time‑sensitive outreach (e.g., last‑minute event invitations), you can send manual one‑off emails directly from a contact’s record. These manual emails are not counted against the 25‑emails‑per‑day automated limit and are dispatched immediately. Use this capability sparingly and follow deliverability best practices.

Important: Contacts cannot be enrolled in multiple sequences simultaneously, even if one sequence is paused. If contacts are already enrolled in a sequence (whether active or paused), they cannot be enrolled in a new sequence until they are completely removed from their current sequence.

If you have already launched a sequence and want to launch a new sequence that should be prioritized, you can temporarily pause the first sequence by navigating to the sequences page, clicking into your sequence, and switching the toggle to 'Paused' in the top right.

Let's you have Sequence A and Sequence B, and you'd like to prioritize Sequence B to be sent over Sequence A. If Sequence A and B are both already launched, you can toggle off Sequence A to a paused state. Sequence B's scheduled email send times will then recalculate and move up to an earlier slot that the Sequence A emails were once scheduled for (if there's no additional backlog on those emails).

Alternative method: You can also prioritize a sequence by dedicating a specific mailbox exclusively to that sequence and removing all other sequences from using that mailbox. This ensures the priority sequence has no competition for sending slots on that particular mailbox.

If Sequence B is not yet launched, you can pause Sequence A before you launch the play that enrolls contacts in Sequence B. This will clear the email queue once paused and free up capacity to send Sequence B emails at an earlier slot. However, contacts already enrolled in the paused sequence will remain enrolled and cannot be moved to other sequences without manual removal.

Time-Bound Campaign Management

For time-sensitive campaigns (such as event-based outreach, promotions, or seasonal campaigns) where emails must be sent within a specific window, you can combine several strategies:

Setting Up a Hard Stop Time Window:

1. Configure a custom send schedule with your desired time windows and skip dates to control when emails can be sent

2. When you reach the end of your desired send window, pause both the play AND the sequence simultaneously:

   • Pausing the play prevents new contacts from being enrolled

   • Pausing the sequence stops all queued emails from sending

3. This dual‑pause approach ensures a complete halt to all activity for that campaign

Preventing Backlog Overflow for Short Windows:

When you have a large contact list but a short time window (e.g., 4,000 companies but only 2 weeks to send):

• Launch the play on a subset first (e.g., a few hundred companies at a time) rather than the entire list

• Prioritize your highest‑value segment and create a sub‑audience to target them first

• Set lower limits in the play (e.g., max prospects per company) to reduce total enrollments

• Route sends across multiple mailboxes to increase throughput and reduce per‑mailbox backlog

This batched approach prevents creating a multi‑week backlog that would extend beyond your event or campaign deadline.