To ensure that the SMTP settings for your iPhone, iPad, or iPod are correctly configured, perform the following steps:
From the home screen on your device, tap Settings and then tap Mail, Contacts, Calendars.
Under Accounts, tap the email account.
Scroll down and tap SMTP under Outgoing Mail Server.
Tap your primary server (secure.emailsrvr.com).
Ensure that Password is selected rather than MD5 Challenge-Response.
Tap the button on the top-left to go to the previous screen, and then tap Done.