As a part of our regular maintenance, the SSL for our outgoing SMTP server (us3.smtp.mailhostbox.com) on Enterprise Email hosted at Austin Data Center is up for renewal.
Post completion of certificate renewal, you might face issues on your Email client, particularly iOS and MAC, stating that the certificate has expired.
In order to resolve this error, you need to re-configure the Email account for the respective Mail client to ensure that the new SSL is fetched for the IMAP server.
You can refer to the following Knowledgebase article on how to resolve this issue :
Please feel free to contact our Support Team in case you have any queries.