Having problems with email on your iPhone? For security reasons, some Internet service providers (ISPs) insist that all their customers’ outgoing mail must be routed through the ISP’s Simple Mail Transport Protocol (SMTP) server. This usually isn’t a big deal if you’re using an email account maintained by the ISP, but it can lead to the following problems if you are using an account provided by a third party:
Your ISP might block messages sent using the third-party account because it thinks you’re trying to relay the message through the ISP’s server (a technique often used by spammers).
You might incur extra charges if your ISP allows only a certain amount of SMTP bandwidth per month or a certain number of sent messages, whereas the third-party account offers higher limits or no restrictions at all.
You might have performance problems, with the ISP taking much longer to route messages than the third-party host.
You might think you can solve the problem by specifying that the third-party host’s outgoing mail is sent by default through port 25. When you use this port, the outgoing mail goes through the ISP’s SMTP server.
To work around the problem, many third-party hosts offer access to their SMTP server via a port other than the standard port 25. For example, the iCloud SMTP server (smtp.icloud.com) also accepts connections on ports 465 and 587. Here’s how to configure an email account to use a nonstandard SMTP port:
On the Home screen, tap Settings.
You see the Settings app.
Tap Mail, Contacts, Calendars.
The Mail, Contacts, Calendars settings screen appears.
Tap the POP account you want to configure.
The account’s settings screen appears.
Near the bottom of the screen, tap SMTP.
Your iPhone displays the SMTP screen.
In the Primary Server section, tap the server.
Your iPhone displays the server settings.
In the Outgoing Mail Server section, tap Server Port and then type the port number.