I’m at the airport in Toronto as I write this.  I got through immigration quite quickly and then my flight was delayed.  So I’m sitting in the lounge using the business center wifi.  Oh, this is odd.  I can’t send email.  I use encrypted SMTP with authentication on port 587 (since ISPs regularly block port 25).  In my case I’m using 1&1 for outgoing mail.  You use the same setup for sending mail through the Gmail SMTP servers.  Works like a charm normally.

Turns out the business center has an SMTP proxy that only listens on port 25.  I was able to send mail by removing authentication and encryption and switching to port 25.  Frig!  I use port 587 so I don’t have to modify my account settings when I switch networks.

I suppose I’m too finicky, if not down-right high maintenance.  Still bugs me.  Sigh.