Gmail (and the gmail-based IU Umail system) 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). This feature is described in this gmail support page:
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.
If this is happening to you and you are not using gmail/umail, then there is no similar simple answer. Possible issues include:
- You are 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 SoIC mailing lists are configured to accept all email from IU email addresses so you could try sending from an IU email account.
- Check your spam folder to be sure the message wasn't tagged as spam and automatically filed somewhere other than your normal inbox.
- If you are using Exchange forwarding rules, they have a bug that can cause confusion. If you set up a server-side Inbox rule (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. This sure seems like a bug in Exchange but there is no know workaround.