All systems are operational
Maintenance
US IMAP email server downtime

On 22 July 2026 at 10:00 am US/Central time (UTC -5) one of our US IMAP email servers will be shut down for infrastructure maintenance. The server will be offline during the maintenance and the expected downtime is 6 hours.

Affected customers will be notified individually via email.

No incoming mail will be lost while the server is offline. Mail that arrives during the maintenance will be deferred and delivered once the mail server is back online.

We realize that the timing of this relocation is not ideal. If you have business-critical mailboxes and would like them to be available during the maintenance then please email support@opalstack.com or reply to this message to make arrangements to have your mailboxes migrated to a different IMAP server prior to the scheduled maintenance date.

If you have any questions or concerns regarding this maintenance then please email the Opalstack support team for assistance.

Past Incidents

22nd December 2021

No incidents reported

21st December 2021

No incidents reported

20th December 2021

No incidents reported

19th December 2021

No incidents reported

18th December 2021

Email: Germany German SMTP blocked by Microsoft

On December 18 2021 at 19:30 UTC Microsoft began blocking mail sent from smtp.de.opalstack.com to domains that use the Microsoft 365 email system.

Microsoft's own IP reputation and junk mail reporting systems indicate that there are no problems with smtp.de.opalstack.com so we've reached out to them for answers.

We'll update this post as soon as more information is available.

In the interim as a possible workaround customers may create a new mailbox on our US mail server and use that temporarily for their outgoing email authentication.

  • We've still not received confirmation from Microsoft that the block was lifted, but we've seen no further blocking activity since 23:50 UTC on 20 December 2021 so we consider this incident to be closed.

  • Microsoft began accepting mail from smtp.de.opalstack.com as of 23:50 UTC on 20 December 2021.

    We're still awaiting official confirmation that the block has been lifted.

    • 17th December 2021

    No incidents reported

    16th December 2021

    No incidents reported