The Connection to the Outgoing Server Failed on My iPhone. Sending email messages from your iPhone uses a different server connection than receiving email.

How to Determine the SMTP Server in Outlook. Like most email clients, the Microsoft Outlook program uses the Simple Mail Transfer Protocol, or SMTP, to process all outgoing messages.

Then, move to the Outgoing Server tab and make sure that the Use same settings as my incoming mail server checkbox is ticked. Lastly, click on the OK button to apply new SMTP settings.

Change SMTP & other settings in your email client Once the above changes are made to the Gmail account, the incoming and outgoing mail server settings need to be configured as well in Outlook ...