Why Doesn't My Custom Mailbox Stay Synced?

Article author
Eric Zrinsky

Sync Mailboxes with UIDValidity

Apollo uses a third-party service called Nylas to connect custom mailboxes to your account. Nylas uses UIDValidity to sync mailboxes on their end. Some configurations lead to inconsistent UIDValidity, which affects sync consistency.

If the UIDValidity of your mailbox changes, Nylas attempts to resync the original value until too many failures cause it to stop. When this happens to a mailbox that you've synced with Apollo, Nylas disconnects it.

Two easy ways to prevent this from happening are:

  • Ensure each folder in your email account has at least one message in it
  • Delete all empty folders in your email account
UIDValidity Guide

For more information on UIDValidity, read Nyla's UIDValidity Guide.

Back to Top

Changes to Your Linked Mailbox that Effect Your Apollo Mailbox Settings

If Apollo can't authenticate your email account's login credentials, Apollo removes the mailbox. Authentication failure can happen for a few reasons:

  • You change your email account password
  • You set up two-factor authentication for the first time
  • You deny Apollo access to your email account
  • You make changes to your email account security settings that prevent Apollo from authenticating your mailbox

If Apollo detects changes to the email linked to the mailbox, Apollo notifies you through email that you have invalid credentials.

Microsoft Exchange

Please note, if you have two-factor authentication enabled for a Microsoft Exchange email account, you must generate an app password from Microsoft. Click here for instructions from Microsoft. You must use the app password to authenticate your mailbox with Apollo. Nylas does not directly support two-factor authentication.

If you delete the email account linked to the Apollo mailbox, Apollo deletes the connected email account.

Back to Top

Re-Link a Mailbox

If you need to re-link your mailbox, please read the Link Your Mailbox to Apollo.io article.

Back to Top