Spam Filtering Known Issues

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Sending Mail

Valid bulk email messages from MIT senders aren't being received by recipients

Users Affected: MIT email senders who use third-party services (such as MailChimp, MailJet, Constant Contact, and IBM Watson) to send bulk messages

Behavior: Microsoft’s Office anti-spam infrastructure has identified some third-party email marketing tools used by the MIT community as potential “bad senders”, causing some bulk messages from these services to the MIT community to be identified as spam.

Status: We are actively working with members of the community who use bulk mailers to ensure email delivery for ongoing and future email campaigns.

Workaround: If you are impacted by this, please report the issue to servicedesk@mit.edu to assist our investigation and receive status updates on this issue.

"Too many hops" bounce error

Users Affected: Users who send mail to mailman lists that contain other mailman lists.

Behavior: The mail bounces with a "Too many hops" error. When you release mailman list messages from moderation, it causes them to go through the mail servers additional times increasing the hop count additional times for each level of nesting (Mailman lists within Mailman lists).

Status: We are aware of the issue and are have implemented a fix to improve the behavior.

Workaround: There is no current solution for existing nested Mailman lists, nor is this a best practice. If you are impacted by this, please report the issue to servicedesk@mit.edu to assist our investigation and receive assistance with your email list architecture to avoid this issue.

Informational: Outgoing.mit.edu no longer accepts unqualified addresses (eg., "ops-help")

Users Affected: Power users

Behavior: outgoing.mit.edu used to accept unqualified addresses (eg., "ops-help") and default them to "@mit.edu". This no longer works.

Status: This functionality is no longer available.

Workaround: Do not use unqualified addresses.

Forwarded Mail

Messages from MIT email addresses are being marked as spam by the external providers receiving forwarded messages.

Users Affected: Forwarding users who are recipients of messages from MIT email users who send mail using a third-party system that has no published has no DKIM, DMARC or SPF information.

Behavior: Users who send messages from a third-party service (such as runbox.com) that doesn't publish DKIM, DMARC or SPF information risk having their messages identified as spam by external providers because the hash or signature does not verify. For more information, see: Email Delivery - Underlying Protocols

Status: Expected behavior

Workaround: Contact the sender to let them know you are having trouble receiving their messages because of the sending method. They can contact the Service Desk for assistance finding a solution that meets their needs.

Messages sent to email addresses in ALL CAPS are not forwarded correctly

Users Affected: Forwarding users

Behavior: Mail sent with a To: address that's in all-caps (e.g., KERBEROS@MIT.EDU or KERBEROS@ALUM.MIT.EDU) may not be delivered if mail is configured to forward to a 3rd-party address. When the email passes through the MIT email infrastructure, the address gets rewritten to its lowercase equivalent, which breaks the DKIM signature. For more information, see: Email Delivery - Underlying Protocols

Status: Expected behavior

Workaround: Contact the sender to let them know you are having trouble receiving their messages because of the sending method. They can contact the Service Desk for assistance finding a solution that meets their needs.

Email Lists

Some string entries to Moira lists are not receiving messages from the lists

Users Affected: Non-MIT e-mail address members of Moira lists (@gmail.com, @media.mit.edu, etc.) and RT users (xxx@help.mit.edu)

Behavior: These users are not receiving mail sent to those Moira lists.

Status: IS&T has resolved it for known instances. Any additional instances found are being handled on a case-by-case basis. We do not yet know the root cause of this issue and are working with Microsoft to determine it.

Workaround: If you are impacted by this, please report the issue to servicedesk@mit.edu to assist our investigation and receive status updates on this issue.

Messages sent to some hidden Moira lists bounce

Users Affected: Members and administrators of hidden Moira lists.

Behavior: Messages sent to some hidden Moira lists bounce.

Status: We are actively gathering information on this issue and have been able to resolve reported instances.

Workaround: If you are impacted by this, please report the issue to servicedesk@mit.edu to assist our investigation and receive status updates on this issue.

Allow/Block Lists

Resolved: The Allow/Block list stops working if you disable "Automatically filter junk e-mail"

Users Affected: MIT email users

Behavior: If you disable "Automatically filter junk e-mail", your personal settings for filtering don't sync, and your Allow/Block lists stop working.

Status: Expected behavior. This is the setting that determines if your personal settings are used to customize spam filtering or not.

Workaround: Select "Automatically filter junk e-mail" in your settings to enable your personal "block/allow" lists.

Informational: Block/allow configurations in O365 Spam Quarantine are no longer working/visible in settings

Users Affected: MIT email users who configured their block/allow lists with O365 Spam Quarantine

Behavior: Block/Allow lists configured in O365 Spam Quarantine are no longer working/visible in settings

Status: Expected behavior. The block/allow lists were unable to be migrated when the filtering system was updated to send Spam to the Junk folder.

Workaround: Recreate the block/allow lists. See: How do I manage my "blocked senders" or "allowed senders" list with MIT spam filtering?

Informational: Block/allow list isn't working

Users Affected: MIT Email users who have not logged in to Outlook Web Access at least once since Junk filtering was enabled.

Behavior: The Block/allow list does not work

Status: Expected behavior.

Workaround: Login to Outlook Web Access to activate your block/allow list.

Other Mail (MTA) Servers

Users Affected: Mail servers that relay mail to the Internet that do not use the IS&T mail infrastructure.

Behavior: Spamhaus (free) RBL is not working

Status: Due to the DNS query volume from MIT, Spamhaus no longer permits the MIT DNS servers to query the free Spamhaus service

Workaround: Contact IS&T for the Spamhaus DQS query key for MIT.

View and release quarantined messages

Microsoft Office 365, MIT's email provider, implements numerous systems to protect users from spam and phishing attempts. Once such system is Microsoft Defender Quarantine, which catches and holds potentially dangerous or unwanted messages.

Sometimes the Quarantine system will hold messages that are safe and should be allowed through. If you suspect an email you're expecting may have been quarantined you can check and if necessary, release it via the Quarantine Tool. 

Read more on Microsoft Defender Quarantine.

See Also

• Email Delivery - Underlying Protocols