If your iPhone, iPad, or iPod touch can receive emails but can’t send them, the issue is almost always related to the outgoing mail (SMTP) settings — even if everything looks correct.
I originally discovered this problem while working at an Apple Store Genius Bar. At the time, Apple did not have an official solution — and even today, this specific fix is rarely explained clearly.
This issue commonly affects non-Apple email accounts such as Exchange, Yahoo, Comcast, AT&T / Bellsouth, and other ISP-hosted email services. Gmail and iCloud accounts are typically not affected.
Quick fix (works for most people)
Re-enter your email password in the outgoing mail (SMTP) settings — even if a password is already filled in.
This single step resolves the issue in the majority of cases.
Primary solution: Re-enter the SMTP password
This is the most reliable fix and should be tried first.
- Open Settings on your iPhone.
- Tap Mail.
- Tap Accounts.
- Select the affected email account.
- Tap the account name again.
- Tap SMTP under Outgoing Mail Server.
- Tap the server listed under Primary Server (it should say “On”).
- Make sure your full email address is entered as the username.
- Re-type your password — even if one already appears.
- Tap Done.
Important: Even if the password field is already populated, you must manually re-enter it for this fix to work.
Once saved, outgoing email typically begins working immediately.
Why this happens
Incoming and outgoing email use separate authentication paths. iOS can retain a valid password for receiving mail while the outgoing SMTP server silently loses authentication — especially after updates or account migrations.
Because the password field often still appears filled in, reinforce authentication by re-entering it manually.
If the main fix doesn’t work
If re-entering the SMTP password doesn’t resolve the issue, your problem keeps going may be caused by one of the following.
Toggle the SMTP server
Turn the primary SMTP server off, wait a few seconds, then turn it back on and tap Done.
Restart your device
A restart can clear cached authentication issues.
Verify server settings with your provider
Confirm the correct SMTP server name, port, and encryption type with your email provider. Apple provides general guidance here:
Apple Mail account settings reference
Remove and re-add the email account
If all else fails, remove the account from Settings → Mail → Accounts, restart your device, and add it again.
Final thoughts
In the vast majority of cases, re-entering the outgoing mail password fixes the issue. This solution has worked consistently for years and remains effective today.
If you discover additional edge cases or provider-specific quirks, feel free to email me so we can keep this guide accurate.
