Exchange Online is the email system in use for all accounts at IU. This system seems to have some optimizations similar to those done on Gmail. For example, if someone sends you a message and CCs a mailing list that you subscribe to, you may only see one copy. Similarly, if a message is sent to 2 mailing lists that you are a member of, you may only see one copy.

Also, with Exchange Online if you set up a server-side Inbox rule (eg. using OWA) that redirects, it will not redirect when the sender address matches the redirect target. This causes confusion when, for example, an exchange group account is created that forwards to a user and the user tries to test it by sending themselves email. If you want to verify that an Exchange group forward is working, you should test it using some non-IU email account and not your normal IU account to work around this problem.

Gmail has a rather annoying "feature" whereby it will not show you email you send yourself. This affects email you send via mailing lists, google groups, and email forwards (such as your @indiana.edu or @iu.edu forward).

Technically, it will not show you messages you send when they arrive back at gmail with the same Message-ID. This is typically the case for mailing lists and forwards. If you are trying to test a forward you should send a test message from an account other than the gmail that is the target of the forward.

It is worth noting that there is another way this issue may manifest itself. If a message is sent such that 2 copies of this same message (with the same Message-ID) reach your gmail inbox, gmail will only show you one copy. For example, if someone sends you a message and CCs a mailing list that you subscribe to, you will only see one copy. Similarly, if a message is sent to 2 mailing lists that you are a member of, you will only see one copy.

There are other reasons that email is not received that can impact all email systems. In some cases, it may be impossible to know why an expected email wasn't received but here are some possible issues:

• You may be sending to a mailing list that you are not allowed to post to. The IU List system will silently reject postings in many cases so be sure you are sending from the same email address that you are subscribed with. Note that most of the Luddy mailing lists are configured to accept all email from IU email addresses so you could try sending from your IU email account instead of your non-IU address.
• You may be subscribed to a mailing list with one address but sending from another. For example, if you are subscribed using your @iu.edu email address but are sending from your @indiana.edu address the mailing list systems will not see those addresses as equivalent, even though both may be delivered to the same inbox.
• Check your junk/spam folder to be sure the message wasn't tagged as spam and automatically filed somewhere other than your normal inbox.
• Be sure to check the Exchange Online and Gmail sections above for issues specific to those systems.