Why Isn't My Custom Mailbox Staying Synced?

We use a third-party service called Nylas to connect custom mailboxes to your account, and they use something called UIDvalidity to sync these mailboxes on their end. Some custom mailboxes are configured so that UIDvalidity doesn't remain consistent, and this is where issues arise. To learn more about this, read their guide on UIDvalidity here.

At a high level though, if the UIDvalidity of a mailbox changes, Nylas will attempt to re-sync with the original value until too many failures cause the sync to stop. When this happens to a mailbox synced with Apollo, it will be disconnected. 

To get around this, they suggest the following:

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

These steps will resolve connectivity issues for some accounts, but not all of them. If this does not work, then your email admin will need to look into how UIDvalidity is managed.

Changes to Your Linked Mailbox that Affect Your Apollo Mailbox Settings

If we are no longer able to authenticate the email login credentials, we will automatically remove that mailbox. This can happen if you change your email account password, set up two-factor authentication for the first time, deny access to your email account from Apollo, or make changes to your email account settings that would prevent Apollo from authenticating your mailbox.

• Important Note: If you have two-factor authentication enabled for logging into an Exchange email account, you'll need to generate an app password from Microsoft using these instructions and use your app password to authenticate your mailbox instead. Note that this is a common authentication issue for those that have two-factor authentication enabled in Exchange as our email service, Nylas, does not directly support two-factor authentication.

Similarly, if you delete the email account linked to your mailbox, we will remove the mailbox since we can no longer sync with that email account.

When we detect these changes to the email account linked to your mailbox, we will send you an email notifying you about your invalid email credentials.

In order for you to continue sending emails via Apollo, simply re-link your mailbox.

Related Resource:

• Link Your Email Mailbox to Apollo