Mailboxes that were added to timetoreply using the bulk add method, should very rarely lose authentication with timetoreply, however, if one does, you can follow the same steps initially used to bulk link the mailbox, to re-authenticate it again.
Go to your name on the top right > Mailboxes > Add mailboxes (multiple at once), select the mailbox from the list of mailboxes presented to you and then click on Save Mailboxes.
Need help or have feedback? Get in touch with us at support@timetoreply.com — we’re happy to help!