I can't send mail from my Comcast smtp account

To make sure all is ok with your account, you could try using Thunderbird instead of Mail and see if it works.

If it works with Thunderbird, then you know all is OK on the Comcast side and there probably is something wrong in Mail's settings.

When you setup an email account in Thunderbirb, make sure you check the option to leave messages on server.

Otherwise, any new messages you will pickup with Thunderbird won't be available the next time you connect using Mail.

It's not that uncommon a problem, Apple has an advice letter on how to troubleshoot it. Please click Mail Can receive email, but not send email and go through the steps. When I had that issue (I'm also using Comcast) what fixed it was re-inputting all the settings even though they appear correct in Mail's settings.

I had the same problem; could not send email from my Comcast account on the Iphone.

I recreated the account but changed the name field to my name (it had been Comcast) and kept just the description as Comcast. Voila, mail started going through. I then changed the name field back to Comcast and mail once again was not being delivered. It seems to be an issue with emails from a user called 'Comcast' being blocked (most likely spam). Whatever the reason, this fixed my issue.

I have had this same problem for a while now. I spent soooooo much time on the phone and with my service providers trying to figure this problem out. Neither was ANY help at all. They actually messed up my contact list and deleted my apps! So frustrating. With this many people having the same issues, I would think that the "professionals" would know how to fix it!

But enough of my venting...I HOPE everyone can find this post easily as it is the only thing that worked for me. I tried everything else under the sun. So THANK YOU YogiBearEatsPie...you have finally helped me solve this problem. I have a Comcast/Xfinity account and an Iphone 4. I hope it works for everyone else too. Do this:

1. Delete email account from phone.

2. Add account again...BUT do as Yogi says and enter your NAME instead of "Comcast" in the top box. You can still leave the description as Comcast if you want.

3. Make sure Primary Server is "ON" if you turned it off prior to this to try to fix the problem.

4. Press your DONE buttons to return back to the main settings screen on your phone.

5. Send yourself an email to test. Good Luck!

wow -- comcast (use have had no issues) with auto configs

but for user name i use full spellling xxxxxxxxx@comcast.net

but the link below will help

http://forums.comcast.com/t5/E-Mail-and-Xfinity-Connect-Help/Screenshots-of-iPho ne-5-mail-settings/m-p/1439257#U1439257

http://customer.comcast.com/help-and-support/internet/email-client-programs-with -xfinity-email/

When I had the same problem with Comcast, aside from deleting/adding an account and re-enter the settings, I also deleted the Mail preference file (which is what stores your settings).

That file is in your User Library. To access that, in Finder, click on the Go in the menu bar while holding down the Option key - your User Library will show in the list. Click and open the Library and scroll down to Preferences. Scroll down there until you see:

com.apple.mail.plist

(you may or may not have a second one: com.apple.mail.plist.lockfile)

With Mail closed/quit, drag one/both into the trash (do not empty yet). Close open windows and restart.

Now start over with Mail/establishing an account (haveing ditched the .plist, you will need to re-enter any changes you had made previously in your preferences there) and see if it'll work.

Going through those steps should also create a new .plist file automatically - you can then empty the trash if you like.