Hey Johnny, I recently installed DECmail-11 on RSTS the other evening, and I'm noticing some undesirable behavior with the mim.stupi.net email gateway going out from inside HECnet. Firstly, it's worth mentioning that gmail won't accept a recipient address with colons in it, unless you put double quotes around it. For example: MARDUK::PHIBER@mim.stupi.net ...won't be accepted as a recipient, and the message is immediately red-flagged in gmail. However, if you do the following: "MARDUK::PHIBER"@mim.stupi.net ...gmail accepts and delivers it, MIM relays it correctly, and I receive the email in RSTS. Nice. Unfortunately, the reverse is failing. If I respond or send mail out from DECmail, mim.stupi.net's sender address rules reject the message: This is Postmaster <MIM::POSTMASTER> at MIM::. I'm sorry, but I could not deliver your mail. An error occured while trying to send it, and I cannot recover. Orignal recipient was &quot;PHIBER(a)PHIBER.COM&quot; Actual error is: Fatal address error. Additional information: 5.1.7 The sender address <MARDUK::PHIBER@mim.stupi.net> is not a valid 5.1.7 RFC-5321 address. h19-20020a05651c125300b0025e725ef592si33185ljh.300 - gsm tp Please let us know if you can correct the sender address restrictions on mim. I tried with quotes, but that didn't help either. :) Thanks, Mark