CISCO 1721 changing SMTP traffic (HELO -EHLO)???

[SebastianMase]

Hello,

Wanting help on a stranbge one...just migrated a T1 user (frac, 768kbps) to provider with PPP encapsulation. Different company as web hosting does allow SMTP traffic if authenticated. Upon changing over T1 provisioning (frame to PPP and different IP schemes) now outgoing email not being authenticated by website company. They reported that there logs show smtp mail attempts are now HELO versus the required EHLO...nothing else on network changed. Could router config (IOS 12.3(15) FW\3DES, CISCO 1721) actually change the type and/or could the PPP configuration somehow affect/change? Thanks in advnace.

Sincerely, MC

 

[jneiberger]

No, the router has nothing to do with this change.

 

[SebastianMase]

Actually, one is suggesting that the ESMTP feature in IOS firewall might be the culprit...stated that they changed it in the router and, behold, smtp traffic now working on mail server...wonder 'bout that.

 

[LarryTheCucumber]

Check your router config and see if smtp fixup is enabled.

If it is it will limit the commands to

HELO, MAIL, RCPT, DATA, RSET, NOOP, and QUIT

All other commands are rejected.

 

[jneiberger]

Ah, jeez, I didn't even think about that. The IOS firewall is attempting to be helpful. I really don't like it when that happens. I had a similar issue with a PIX where it was trying to be "helpful" and it ended up completely breaking a video conferencing application.