On 10/15/2015 01:04 PM, walt wrote: > My ISP recently started offering imap email service in addition to > the pop3/smtp servers they've always had, so I decided to try it. > > I was surprised to see that they recommend using a different smtp > server name when setting up my mail client, and they even offer the > option of using port 587 instead of 465 if I prefer it. > > ... > > (The different server names actually resolve to the same IP address, so > the distinction seems to be more theoretical than real, but the theory > is what puzzles me.) >
Port 587 offers optional TLS security, and it uses an "SSL certificate" just like a website. And just like a website, there's a name on the certificate, and that name has to match what you type in the "SMTP server" box, otherwise your mail client will throw a warning.
