Community Forum

Unable to Send Emails

New Poster

Unable to Send Emails

For the past 24 hours I have been unable to send outgoing email.  When I try I get the following verbatim message: "An error occurred while sending mail. The mail server responded: 5.1.0 Authentication required. Please verify that your email address is correct in your account settings and try again."

 

I have checked and, yes, my email address is correct in my account settings.

 

I use Thunderbird 60.9.0 as my email program.

New Poster

Re: Unable to Send Emails

Me too. As of sometime this morning. I use Outlook but get the same message you are getting.

New Poster

Re: Unable to Send Emails

I receive the following error message when trying to send emails from outlook 0x800ccc78

verify email address in account properties. Server respond 550 5.1.0 Authentication required.

 

New Poster

Re: Unable to Send Emails

I'm getting the same exact message for two days.  Called Xfinity and was told to call Microsoft.  They gave me a number that was not in service.  Great help.  It has to be an issue with the Comcast server.  

Contributor

Re: Unable to Send Emails

Agreed re server problem. If still a problem in the morning I will also try calling Comcast. May even post on Facebook as sometimes that gets attention.

havent changed anything on my PC that pertains to Microsoft so can’t see how that would suddenly be a problem.

New Poster

Re: Unable to Send Emails

I also can not send emails. Noticed it yesterday morning.

Same using Thunderbird 60.9.0 no other Windows changes and virus scan is clean.

Reciving emails works. Just can't send my own emails even to gmail account.

Tried chat with agent but nothing yet.

Sure seems like an outgoing email server.

Contributor

Re: Unable to Send Emails

Still happening to me as well. I also recieve but cannot send with Outlook.

Frequent Visitor

Re: Unable to Send Emails

Please check your outgoing mail server settings in Outlook and be sure that the security settings are set to TLS or Auto. It looks like Comcast is requiring TLS when connecting to smtp.comcast.net (outgoing mail). Previously it allowed SSL which is a weaker algorithm.

 

New Poster

Re: Unable to Send Emails

THANK YOU!

Changed the outgoing server to TLS normal password and it works!

Contributor

Re: Unable to Send Emails

I dont have tls or auto option

Frequent Visitor

Re: Unable to Send Emails

Have a look through this thread. They discuss changing the settings in Outlook.

https://forums.xfinity.com/t5/Email-Web-Browsing/Can-t-send-emails/m-p/3266721/highlight/true#M21234...

 

Contributor

Re: Unable to Send Emails

I was just on the phone with an extremely helpful Comcast person. It seems that Comcast is aware that there is some sort of bug that they are working on to fix. It applies not only to Outlook but also some other email programs.  It may take up to 24 hours to repair but he said I would be notified when they believe they have fixed the problem.

Unfortunately I do not remember his name, but I will repeat, he was extremely helpful and spent time trying to find out what is going on.  He also said that Comcast is aware of all the problems people are having with sending out emails.

 

So hang in there

New Poster

Re: Unable to Send Emails

I finally got my outgoing to work last night.  For some reason the security box for Incoming SSL and outgoing box TSL needed to be checked.  Previously I had only had the incoming box checked.  No idea what or why it changed.  Just glad to have it working again.  I was disappointed that Comcast couldn't have given some basic help after how much I pay each month. 

New Poster

Re: Unable to Send Emails

Thank you for the suggestion, russauld.  This worked for me as well.  I hope everyone's issues with this get resolved.

Contributor

Re: Unable to Send Emails

Comcast has now downloaded all my emails from 2015 on to my outlook program. over 900 emails it has brought back!!!! 

  Maybe that is part of their fix???

I may have gotten send to work by checking SSL for both incoming  and outgoing. I do not have TSL option. Ports are 995 and 587. Not sure  if this is a permanent fix nor if I will get only new emails from now on or not.  will keep trying to everything works the way it should

Contributor

Re: Unable to Send Emails

Correction Comcast has now downloaded to Outlook my emails from 2006 till 2019 Yikes!!

New Poster

Re: Unable to Send Emails

I too have been having trouble sending emails through my Thunderbird program since the 4th.  After reading through several posts made here I decided to go back into my Thunderbird program to check the settings.  I went to Tools, then to Account Settings.  I clicked on Outgoing Server and then Edit.  I opened Connection Security, and I don't remember if I had it put it on a different setting previously and it mysteriously changed without my doing but it was currently set at NONE so I hit the drop down and changed it to SSL/TLS and hit OK.  Also, my outgoing port is set to 465.

This change allowed my outgoing emails to go through with no more error message.  I sent emails to several friends who verified their reciept just to make sure.  I hope this helps some of you with the problem.

New Poster

Re: Unable to Send Emails

me too

I did go to settings and changed the outgoing server security to SSL and it worked. Thanks

New Poster

Re: Unable to Send Emails

UNABLE TO SEND as Well

New Poster

Re: Unable to Send Emails

change your outgoing "setting" as describe a few posts above- it worked for me.

New Poster

Re: Unable to Send Emails

after 2 days it finally worked for me. Went to "advanced" tab, "outgoing" set to "use SSL secure connection" -- port defaulted to "25", changed it to 587 after setting to use SSL. Thought i had done this a day ago -- this time it worked.

New Poster

Re: Unable to Send Emails

I've been struggling with this since around the 4th as well with SeaMonkey. I finally found the place in the outgoing server to change it from none to SSL/TLS and it worked for at least one email. Comcast help was virtually worthless, just telling me that they were no longer supporting anything but comcast email. That's not very helpful.

New Poster

Re: Unable to Send Emails

I am also no longer able to send outgoing emails from an older application that I've been using for years.  The only settings that it includes are the server name (smtp.comcast.net),  port (587), and username/password.  There is no options for which type of security to use; all this is internal to the program.  I also am getting the 500 1.0.0 error, which claims to be an authentication problem.

 

From reading all these emails, are people saying that Comcast has permanently changed their security protocol on outgoing emails?  Or is this a "bug" or something else that Comcast plans to fix?  

New Poster

Re: Unable to Send Emails

I can't send from my livemail.  It worked fine earlier but now I get the error pasted below this message.  I can send from the comast email website, but not from my livemail program.  Why would it not recognize my email when I'm sending emails but I'm receiving emails without any issue? My setup has not changed since three hours ago when it worked great. ????

 

Anne Marie Baugh

Jeff Baugh.... see error below....

 

The message could not be sent because the server rejected the sender's email address. The sender's email address was 'my email was here but I removed it for the forum post'.

Subject 'test'
Server Error: 550
Server Response: 550 5.1.0 Authentication required
Server: 'SMTP.comcast.net'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 587
Secure(SSL): No

Frequent Visitor

Re: Unable to Send Emails

As discussed in this thread, you MUST enable SSL/TLS on the outgoing mail server connection.

 

Frequent Visitor

Re: Unable to Send Emails

 @1internetsmarty :

Yes, you must use TLS protocols to connect to their outgoing mail server. Your old client application may not support the more modern TLS security model.

If it supports SSL at all, it might use the older insecure SSL protocol versions. Since you are transmitting your username and password when you communicate with the outbound mail server (sending mail), your session could be vulnerable and someone could obtain your password.

This is why they've (apparently) decided to require TLS as it is more modern and secure.

You may need to switch to another client application if you cannot get an updated version with TLS support.

 

Frequent Visitor

Re: Unable to Send Emails

What is "TLS Normal Password" and where would I find it?

Frequent Visitor

Re: Unable to Send Emails

This still does not work for me, changed to SSL Required and Port 465 and "Nada" - still getting error message

New Poster

Re: Unable to Send Emails

Would you be able to recommend another email client?  Livemail is all I've ever used and it's not longer supported.  Thank you so much.

Frequent Visitor

Re: Unable to Send Emails

@1internetsmarty  Accoring to this article Windows Live Mail does support TLS. 

 

Frequent Visitor

Re: Unable to Send Emails

@donjerue1 Could you share the details of your mail client with us? Please include operating system version, name of mail client software, and its version.

 

New Poster

Re: Unable to Send Emails

Yes, I'm aware.  It's not a supported email client by Window's any longer.  What email client do you recommend.  Thank you, by the way.  :-)

New Poster

Re: Unable to Send Emails

I am using MS Outlook 2003. Does not have option for TLS. I am now successfuly using Outlook after many trials and resets etc.

Use SSL if you dont havre TLS

Use pop3.comcast.net for incoming mail server and SMTP.comcast.net for outgoing server.

Incoming server 995, outgoing server 465.

Check boxes for both for server requires an encrypted connection. I had to NOT check the box that says choose logon using secure password (SPA). I just kept setting and resetting 

Also, in my case somehow they had downloaded old emails which I then had to work with Outlook files to make sure they were the correct ones. But you have to know something about how the Outllok files work in order to do that. '

After 4 days of this I finally got it to work.

A Comcast tech did call and we were on the phone for almost an hour or so. he kept telling me to change things that I had already changed.  He kept telling me that theses changes were spposed to have been made almost a year ago. He finally said the problem is a Microsoft one ( was not)  and that was the end

. I have made all changes they have suggested each time Comcast said to. This problem has happened to so many of us that I believe that someone messed up and that is why we are all in this mess and Comcast is passing the buck to Microsoft. . 

There are some non Comcast online web sites that, if you type in a question and do a search, they may be able to help you via a chat. Some are free.

Good Luck to all  if you haven' been told the problem is some other software try calling Comcast for help . Good Luck!!