Mailbox user assignment

Last updated: May 5, 2026

What does associating a user with a mailbox do?

Each Unify managed mailbox has a user associated with it. Replies to emails that come from that mailbox will then be forwarded to the user's email. Note that automated responses such as out-of-office (OOO) messages are not forwarded to your inbox, but can still be viewed within the Unify platform. You can view these replies in two locations: within the Unify platform (Tasks Dashboard or the "Replies" section of the Lagging Dashboard) and in your primary email inbox.

Creating and assigning a mailbox to a user is only the first step. To actually use your mailboxes for sending emails, you must configure mailbox routing in your sequence settings. Mailbox selection happens at the point of enrollment, not during sequence creation. You’ll select mailboxes or mailbox groups when: (1) one‑off sequencing through the Chrome extension or by right‑clicking someone in Unify, (2) bulk sequencing through a list, or (3) programmatically sequencing via a play (configured in the sequence node routing settings described below).

  1. Go to Play Builder and open the play containing your sequence

  2. Select the Sequence node

  3. In the Routing section, click “Edit persona routing” (not the mailbox count)

  4. Add the mailboxes or mailbox groups you want to use for this sequence

  5. Save your changes

  6. Republish the play so changes take effect

Manual Mailbox Selection

Select specific mailboxes you want to include in the sequence. Only mailboxes added to sequence routing will be active and used for sending. Unify assigns contacts to mailboxes using round‑robin rotation at the contact level, which means multiple contacts from the same company may be assigned to different mailboxes and receive emails from different senders. This allows you to control exactly which mailboxes are used in each play and helps distribute email volume across multiple mailboxes to increase your sending capacity.

Note: If maintaining consistent sender identity per company is important for your outreach strategy, use owner‑based routing instead, which ensures all contacts from the same company receive emails from the same mailbox.

Owner-Based Routing

Select “Use a mailbox associated with the company/person record owner” to automatically match record owners to their assigned mailboxes. This ensures that leads owned by specific team members will only send from that person's mailboxes, maintaining consistent sender identity throughout the entire sequence.

  • There is no automatic fallback if a mailbox in your round‑robin rotation hits its daily send limit

  • Reply tasks will also round‑robin to the owners of the selected mailboxes

  • Each team member needs mailboxes properly assigned to them in Settings → Deliverability → Mailboxes

  • Team members need to log into Unify at least once to associate their name with their mailboxes

  • You can configure fallback mailboxes for cases where a record owner doesn't have assigned mailboxes or their mailboxes are at capacity

Understanding Daily Sending Limits

Each mailbox has a daily sending limit (typically 25 emails per day for Unify-managed secondary domain mailboxes, while primary domain mailboxes can have higher limits up to ~65 emails per day), so adding multiple mailboxes to your sequence routing increases your total daily sending capacity – for example, 5 mailboxes would allow 125 emails per day across that sequence.

Primary Domain Mailbox Limitations and Scaling Options

When planning your mailbox strategy, it’s important to understand the differences between primary domain and Unify‑managed secondary domain mailboxes. Primary domain mailboxes cannot be newly provisioned; you are limited to the existing ones, but they can have higher sending limits than the standard 25 emails/day.

  1. Increase Primary Domain Limits: Request to increase your existing primary domain mailbox sending limit up to approximately 65 emails/day for deliverability reasons.

  2. Add Secondary Domain Mailboxes: Supplement your primary domain mailbox with Unify‑managed secondary domain mailboxes (25 emails/day each).

  • 1 primary domain mailbox = up to ~65 emails/day (can be increased upon request)

  • 1 primary + 2 secondary domain mailboxes = ~115 emails/day

  • 1 primary + 5 secondary domain mailboxes = ~190 emails/day

When designing your sequences, calculate your daily enrollment needs against your available mailbox capacity to ensure smooth delivery without hitting limits.

Note: While replies are forwarded to your inbox for visibility, you must respond from within the Unify platform for the system to recognize your response and complete associated tasks. If you're not seeing forwarded replies in your inbox, check your spam/junk folder or corporate email filters. To reduce the likelihood of this happening in the future, mark these emails as "not spam" when you find them in your spam folder. For a more proactive solution, consider whitelisting your Unify mailbox domains in your email provider settings to prevent legitimate replies from being flagged as spam.

When a user is removed from the platform or when you change mailbox assignments mid-sequence, you may need to reassign tasks and emails:

  • Tasks: Can be bulk reassigned via Dashboard → Tasks tab by selecting all relevant tasks and choosing "Assign Owner"

  • Queued emails (Step 1 only): Can be bulk reassigned via Dashboard → Leading → Email Backlog → Reassign Sequence Enrollments for that sequence

  • Mid-sequence scheduled emails: Cannot currently be bulk reassigned and would need to be updated manually

Mailbox Reply Forwarding with Multiple Mailboxes

When you have multiple mailboxes assigned to you (such as in a mailbox group with rotation), it's important to understand how reply forwarding works:

  • Replies will be forwarded from whichever specific mailbox in your group sent the original email, not necessarily your primary inbox

  • When responding to prospects, Unify automatically sends your reply from the same mailbox that received the prospect's response, ensuring proper email threading and deliverability

  • If you're expecting a reply but don't see it in your primary inbox, check the specific mailbox that sent the original email

This automatic mailbox matching prevents email threading issues and maintains consistent sender identity throughout your conversation with prospects.

Can I create a mailbox on behalf of someone that is not a user in Unify?

We do not recommend this approach - the mailboxes you create on Unify should be associated 1:1 with the assigned user. You would need to use an additional sequencing seat if you're adding mailboxes on behalf of another member of your team. We use the name associated with the user to populate sender variables and the signature.

We generally do not recommend associating a different user or a generic email such as hello@unifygtm.com or sales@unifygtm.com to adhere to CAN-SPAM regulation. For example, if you were to create bob@tryunifygtm.com - you will need to associate this mailbox with an individual user dedicated to Bob with his actual email assigned to the user. We offer a secondary forwarding option on your Unify managed mailboxes in case you want the replies to go to both the assigned user’s email and another mailbox. To configure secondary forwarding on Unify managed mailboxes, contact the Unify team as this setting is not currently available in the UI.

Email signatures are configured within the Unify platform under Settings → User → Signature; they are not pulled from your Gmail or other email provider settings.

Task Assignment vs. Mailbox User Association in Unify

While Unify enforces a 1:1 relationship between mailboxes and users for personalization and compliance reasons, task assignment can be configured independently through sequence settings. This allows you to maintain proper mailbox‑user associations while routing workflow tasks to different team members.

How to Configure Independent Task Assignment

Request mailbox rewarming for reassigned mailboxes – this process typically takes ~1 week and is essential to maintain deliverability when mailboxes change hands.

  1. Navigate to your sequence settings

  2. Go to Advanced Settings

  3. Select "Manually Assign Tasks"

  4. Choose the user who should receive tasks for this sequence

This configuration keeps the correct sender information and personalization (using the mailbox user's name and signature) while directing all sequence tasks to your preferred team member.

When This Is Useful

  • Team lead oversight: Mailbox belongs to a rep, but tasks route to their manager

  • Specialized roles: Technical sequences use engineer's mailbox but tasks go to sales rep

  • Coverage scenarios: Maintain personalization during team member absences

  • Workflow optimization: Route tasks based on expertise rather than mailbox ownership

Important: This approach maintains CAN‑SPAM compliance and proper personalization since the mailbox‑user relationship remains intact. Only the internal task routing changes, not the external email sender information.