PostPosted: Mon Jan 24, 2005 6:52 pm Post subject: PPPoE and Linksys router Reply with quote Back to top Just as a help for anyone else who may run into this problem: I posted a question last week about not being able to send email with the Vonage Linksys router as the first device in a daisy chain. Turns out the problem was more generic than that.
If you have PPPoE (like DSL or, as in my case, Verizon FIOS fiber to the home) you MUST change the MTU size from default (which is 1500) to 1492. The issue is with large packets (like attachments) the mail server failed to recieve the entire message and therefore failed the checksum causing the message not to go thru. This is because every packet will be missing 8 bytes. It may seem intermitent as small messages go thru fine and of course downloads are restricted by the network so they work fine too.
Just a word to the wise. Wink