iPhone includes preset configurations for many of the popular providers such as Yahoo! Mail, Gmail, .Mac, and AOL, and in most cases sending mail will just work.

However if you are using a different provider than above and your ISP is blocking port 25, you may see a message that email couldn't be delivered because the connection to the server on port 25 timed out.¹

If this is the case, try the following:

• Make sure the Outgoing Mail Server (SMTP) section is properly set up on the iPhone (Hostname, User Name, and Password if necessary). To access these settings, tap Settings > Mail. Then tap the account you want to check.
  
  
• iPhone will allow you to specify a port to use. To do this, tap Settings > Mail. Then tap the account you want to change, and in the Outgoing Mail Server (SMTP) Host Name, add at the end of the name a colon and the port number to use.
  
  Example: If you enter smtp.att.yahoo.com:587 then iPhone will use smtp.att.yahoo.com as your SMTP server with port number 587.
  
  
• Ask your ISP if they are blocking port 25 and if you can use any return address, or if you are required to use the address you have with them.
  
  
• If your ISP is blocking port 25 but not port 587, change the port to 587 and try again.
  
  
• If you know your Outgoing Mail Server (SMTP) requires authentication try the following:
  1. Under Advanced, make sure that SSL is on for the Outgoing server.
  2. Make sure that the authentication method matches your server configuration (Password is the most common setting).
  3. Try sending mail again.
  4. If it still doesn't work, change the port to 465 for the Outgoing Mail Server (SMTP) and try again.

1. Port 25 is the port used to send email via the Internet. Some Internet service providers (ISPs) block port 25 when you are outside the ISP's network, to reduce the amount of junk mail originating from their domain. By blocking port 25, the ISP forces its customers to use the outgoing (SMTP) mail server provided by the ISP, rather than the SMTP server on their computers, so the ISP can monitor the outgoing mail and track down junk mail senders.

Labels: iPhone