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Thomas Z
Thomas Z, Mac Genius
Category: Mac
Satisfied Customers: 172
Experience:  15 Years of Personal Experience on Mac, 6 months full time Computer Tech with Mac specialty
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I have a fairly new 3g iphone..receive mail fine to 3 mail

Resolved Question:

I have a fairly new 3g iphone..receive mail fine to 3 mail accounts...recently my outgoing mail stopped being sent with error message "CANNOT SEND MAIL THE SENDER ADDRESS ISN'T VALID". Nothing in my settings has changed as far as I can see. I sync'd and restored twice to no avail..when i send from my aol address through their smtp mail goes other smtp gives me the invalid sender address errors...
Submitted: 7 years ago.
Category: Mac
Expert:  Thomas Z replied 7 years ago.
Go to Settings --> Mail
Choose your optonline account
scroll down to outgoing server and put:
username: Myoptonline (Your username - this is the first part of your e-mail before the @ sign)
password: ********* (Your Password)

Click "advanced"
Make sure SSL is OFF
Make sure authentication is set to "password"
Customer: replied 7 years ago.
smtp account verification failed the smtp server "" is not responding. check your network connection and that you entered the correct information in the "outgoing mail server" field
Expert:  Thomas Z replied 7 years ago.
Try this:
1) Click "Settings" on your home page
2) Click "Mail, Contact, Calendars"
3) Select the Account you are having the issue with (Optimum)
4) Scroll down this page and click Outgoing Mail Server (SMTP)
5) Turn all the Servers OFF except AT&T SMTP Server (Turn This ON)

This will use AT&Ts SMTP server and will fix your problem.
Customer: replied 7 years ago.
Doesn't that take you off the 3G network?
Expert:  Thomas Z replied 7 years ago.
Not that I am aware, I just did it to mine and I am still on 3G.
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