It is advisable to use the math department email as little as possible. There is a good amount of spam since the department publishes those email addresses publicly, and the spam blocking system they set up has a high number of false-positives, so you'll have to read through all of the spam headers anyway.
In addition, we've received email like the following: Last Friday we discovered that there was a problem with the spoofer checking software that could have prevented some valid email from being delivered to you. .... Below is a list of email addresses since, --, that tried to send you email but was blocked. Check the email list below and contact any sender address that you think might be a valid email.