Force Mail to send thorough a specific interface?

[GeeYouEye]

My university has a wireless network and a wired network, and I have a powerbook, which I typically keep connected to the LAN when I'm in my room, but I leave the AirPort card on (get many more iTunes shares that way!). Unfortunately, they block port 25 on the wired network for any mail server except their own, but they don't for the wireless network. This isn't THAT much of a problem, but it means that I have to disconnect from the LAN and re-login in Mail any time I want to send a message from any account other than my .edu address (university mail server doesn't like From addresses that aren't from its domain 😡 ), since Mail defaults to sending over en0 (ethernet). Is there anyway to force Mail to send on en1 (AirPort) instead, even when connected to the wired network?

 

[mkrishnan]

I wonder if this can somehow be done with locations?

I don't have an answer 🙁 but out of curiosity, why don't you just use the wireless network over which you're able to hit your SMTP? Are you transferring enough file bandwidth with other applications or running a remote X client or something, that you don't have sufficient transfer speeds wirelessly?

Related to this is a question I've asked around a few times, to which I think there is also no good solution, which is to force Mail to automatically use different SMTPs when connected to the net via different networks. Because I have a variant of the same problem, except that all my connections restrict SMTP to their server only (all different), and only one is available at the same time, so if I configure my Mac to work at home, I have to wait for an email to bounce and then do the requester in Mail to change SMTP servers...and if it goes to sleep, repeat! 🙁