Scott Davis has made an important discovery 
about SMTP ports. As a result, he no longer has to choose between email and coffee.
Setting his outgoing SMTP server in Mail.app to use port 587 means that he can now knock back his lattes at Starbucks and send emails at the same time.
The breakthrough came after years of frustration. He didn’t want to sacrifice the beauty of Apple Mail for a web-based service that would have provided him with a work-around for Starbuck’s blocked port 25:
I used Yahoo mail as my primary client for years. But once I got started using Mail.app, the thought of going back is singularly unappealing. (Yeah, GMail as well…) Plus, I’ve started to depend more and more on Spotlight to retrace my steps. (”I said what? When? To who? What was I thinking?”) Doing a non-insignificant portion of my emailing out of band was really beginning to cramp my style.
Gmail may not be the answer, but Google was his friend:
… what pushed me over the edge was the fact that port 25 was progressively getting blocked in more and more places. Starbucks, hotels, and finally my Mom’s Wifi connection at home. Allow me to repeat that in case you missed it: I COULDN’T EMAIL FROM MY MOM’S HOUSE. Something had to change.
Out of desperation, I Googled “apple starbucks send email”. At the end of one message thread, someone cryptically suggested changing port 25 to 587. No explanation, and no report back of whether it succeeded or not. I began Googling more: “starbucks port 587″, “secure smtp port 587″, etc. Apparently, all of the cool kids use port 25 for server-to-server communication and use port 587 for message submission.
Gmail offers port 465 with SSL for its smtp.gmail.com server, although it rewrites the from address on any email sent that way to identify you by your Gmail address, unless you set another email address as your default in Gmail’s settings (see more on this at Lifehacker). Not always a good look.
Fastmail offers port 26 and 465 with SSL as work-arounds.
.Mac likes port 587.
Your ISP might offer a way to extend your stay in Starbucks too.
