Warning: Inbound/Outbound Mail Routing Issue (PowerShell Cloud Module v2.5.0)

Summary

We have identified an issue in the recently released PowerShell Cloud Module version 2.5.0. A regular expression (regex) failure in this version causes outbound emails to bypass the designated outbound connector, delivering them directly through Exchange Online (EXO) instead.

Impact

If you have deployed or updated transport rules using version 2.5.0, your outbound mail routing may not be processing as intended and will bypass the seppmail.cloud secure gateway.

Immediate Mitigation Steps

If you have already created or updated transport rules using version 2.5.0, you must correct the exception regex string to restore proper mail flow.

PowerShell Fix (Recommended)

Connect to Exchange Online PowerShell and run the following command to update the exception pattern on the rule:

PowerShell

Set-TransportRule -Identity ‘[SEPPmail.cloud] - 200 Route outgoing e-mails to SEPPmail’ -ExceptIfFromAddressMatchesPatterns ‘^$|^<>$’
Note: A permanent fix is being integrated into Release 2.5.1, which will be available shortly. If you have not yet updated to v2.5.0, we highly recommend skipping it and waiting for v2.5.1.