322434 - Warn about SMTP redirection

Status: NEW

(MailNews Core :: Networking: SMTP, enhancement)

Description

[Simon Blanchard]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8) Gecko/20051111 Firefox/1.5
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8) Gecko/20051111 Firefox/1.5

A network provider had re-directed all SMTP port 25 traffic to its own servers (as a "convenience" for hotel guests!) Thunderbird tried to send email using the re-directed servers - no error message was given that it has connected to a different server than the one specified in the preferences. I think a check should be made - for example reading the ELO response - to make sure that where you are and where you think you are are the same place.

Reproducible: Always

Steps to Reproduce:
1. Connect to network with port 25 re-direction


Actual Results:  
SMTP goes to the re-directed servers

Expected Results:  
An error is given about the re-direction. Option to abort/continue.

Comment 1

[Wolfgang Rosenauer [:wolfiR]]

It's not so easy to detect this without creating many false positives I think.
Many mailservers are published as "mail.domain.xy" or some other alias while internally they use another hostname. The same for load balancing setups and so on. So what would be a reliable way to detect that you didn't connect to a different SMTP host? 
Please note that SSL/TLS connection solves the problem.

Comment 2

[Gervase Markham [:gerv]]

As Wolfgang says. SSL is the way to solve this problem. After all, if you are sending unencrypted messages over an unencrypted connection, you don't care which machines they pass through or who reads them, right? :-)

Gerv

Comment 3

[timeless]

declassifying

Comment 4

[Daniel Veditz [:dveditz]]

I've reworded the summary to be an enhancement request so I can confirm it, which will make the bug more visible to developers. I suspect this is a WONTFIX though, for the reasons stated in the comments