U

Visitor

 • 

1 Message

Saturday, April 1st, 2023 10:32 AM

Closed

Mail Issue - Getting ESMTP error on IPV4

Hello,


Recently when we are trying to send message through our mail servers to subscribed comcast customers, we are getting below response(Error Message) from Comcast: smtp;554 resimta-c1p-044889.sys.comcast.net resimta-c1p-044889.sys.comcast.net ESMTP server not available.

While checking Comcast blogs and community posts i came to know this error arrises when there is Reverse DNS issue, but my IP has proper RDNS, also we are following all. protocols like SPF, DKIM and other. Suggest what should we do to solve the issue.


Lewis

Problem Solver

 • 

1.5K Messages

2 years ago

ESMTP server not available

Kind of a catch all that could mean anything from your domain is on an RBL list they're using and they're not telling you which one, you got flagged and blocked for too many recipients/large attachments/too many BCC's, you triggered an internal spam or virus filter and the content of your message is considered "spam" and bounced....etc.

Can you send one email to one client and not blast with a list?  I'd try that first.  Mailing lists are problematic. 

You can also try contacting them.  Perhaps your domain is currently blocked.  That happens.  That also happens if you are trying to run a mail server on an ISP's non-business account DHCP pool -- we're all blocking those.    

  • Business Hours: 8:00am - 12:00am EST, 7 days a week
  • Contact: 1(space)888(space)565(space)4329

*The bot ate the last one for posting an Xfinity phone number (personal info), so I'll try that again.

Gold Problem Solver

 • 

26.4K Messages

2 years ago

smtp;554 ​... ESMTP server not available​

If you view the raw source of the bounce email you should find additional information explaining what the problem is.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

(edited)

Official Employee

 • 

903 Messages

2 years ago

Sharing your IP addresses (and maybe domain) would be a big help @user_d5d0a7 

forum icon

New to the Community?

Start Here