Ecelerity

[PK88]

Users of a regional ISP that use their ISP’s email server are receiving rejection notices when they send emails to users on my email server.  The error message sent back to the ISP user indicates “the address failed”, “550 5.0.0 Access denied“, but a check of my logs indicate that the ISP’s email server did not even make an attempt to deliver the mail. 

The only thing that might suggest what is going on is that error message appears to be created by “ecelerity” which I assume is some sort of commercial filtering software. 

Does anyone know if ecelerity tends to block for some period of time as some DNSBLs do, or if it is a permanent block?

It really has me baffled.  I could see if it blocked email “from” my server if it thought it was spam etc., but why would it block “inbound” email to my server?  Why would it care what email my email server accepts?

 

[Admin]

Hi. It is strange that the ISP's email server isn't even attempting to deliver the mail and you're only receiving rejection notices with an "ecelerity" mention. Here's what could be happening:

Ecestoration block: Ecelerity offers email filtering and security services, including email gateway protection. It's possible the ISP uses Ecelerity for inbound email filtering, and Ecelerity has flagged your domain or IP address as suspicious, triggering a temporary or permanent block for all incoming emails destined for your server.

Misconfigured spam filter: A misconfiguration in the ISP's spam filter, possibly involving Ecelerity integration, could be causing emails to be rejected before reaching the mail server. This could be due to incorrect sender domain reputation scoring, content-based filtering rules, or a technical issue.

Other filtering services: Less likely, but the ISP might be using another filtering service besides Ecelerity that's responsible for the block. Check if they mention any other anti-spam/security partner in their documentation or support website.

Here's what you can do:

Contact the ISP: Reach out to the ISP's technical support and explain the situation. Tell them about the "ecelerity" mention in the rejection notice and ask if they use Ecelerity for inbound filtering. Request them to investigate the block and provide information on its nature (temporary/permanent) and reason for triggering.

Check your server logs: Look for any additional details in your email server logs related to the rejected emails. Maybe you'll find more clues about the specific rule triggered by Ecelerity or another system.

Review your server reputation: Check your domain and IP address reputation on blacklist monitoring services like MXToolbox or Spamhaus. See if you're listed on any spam blacklists, which could be feeding negative signals to Ecelerity or other filtering services.

Reach out to Ecelerity: If you manage to confirm the block originates from Ecelerity, you could try contacting them directly for further information. Explain the situation and the lack of delivery attempts, and see if they can provide insights or guidance on resolving the issue.

And, blocking inbound email to your server is unusual, and you need to get to the bottom of it. Be persistent in your communication with the ISP and consider exploring all the avenues mentioned above to clarify the situation and hopefully get the block lifted.

I hope this helps!

 

[PK88]

Hi. It is strange that the ISP's email server isn't even attempting to deliver the mail and you're only receiving rejection notices with an "ecelerity" mention. Here's what could be happening:

Just to clarify, I am not receiving any notifications of delivery failure. At my end I am seeing nothing in the logs of even an attempted delivery.  The only reason I know of the failures is because I am being contacted by users of the ISP by other means indicating they are receiving messages from the ISP's mail server of delivery failure.  It is their rejection notices that they have passed on to me that indicate it could be based on an "ecelerity" filter.

Ecestoration block: Ecelerity offers email filtering and security services, including email gateway protection. It's possible the ISP uses Ecelerity for inbound email filtering, and Ecelerity has flagged your domain or IP address as suspicious, triggering a temporary or permanent block for all incoming emails destined for your server.

Misconfigured spam filter: A misconfiguration in the ISP's spam filter, possibly involving Ecelerity integration, could be causing emails to be rejected before reaching the mail server. This could be due to incorrect sender domain reputation scoring, content-based filtering rules, or a technical issue.

Other filtering services: Less likely, but the ISP might be using another filtering service besides Ecelerity that's responsible for the block. Check if they mention any other anti-spam/security partner in their documentation or support website.

All good points

Here's what you can do:

Contact the ISP: Reach out to the ISP's technical support and explain the situation. Tell them about the "ecelerity" mention in the rejection notice and ask if they use Ecelerity for inbound filtering. Request them to investigate the block and provide information on its nature (temporary/permanent) and reason for triggering. 

Check your server logs: Look for any additional details in your email server logs related to the rejected emails. Maybe you'll find more clues about the specific rule triggered by Ecelerity or another system.

There is nothing in my logs.

Review your server reputation: Check your domain and IP address reputation on blacklist monitoring services like MXToolbox or Spamhaus. See if you're listed on any spam blacklists, which could be feeding negative signals to Ecelerity or other filtering services.

 

I have checked www.dnsbl.info over the years and have never seen a problem, and it currently reports no problems. Similar sites show the same results.

Reach out to Ecelerity: If you manage to confirm the block originates from Ecelerity, you could try contacting them directly for further information. Explain the situation and the lack of delivery attempts, and see if they can provide insights or guidance on resolving the issue.

It appears that Ecelerity was originally a product of OmniTI that was taken over by Credativ, which in turn was absorbed by NetApp. After that I hit a dead end . There is a www.ecelerity.com (https://www.zoominfo.com/c/ecelerity-inc/40291961, but that site is currently offline.  Based on what little I could find about them though, it appears they have little to do with email.

And, blocking inbound email to your server is unusual, and you need to get to the bottom of it. Be persistent in your communication with the ISP and consider exploring all the avenues mentioned above to clarify the situation and hopefully get the block lifted.

I hope this helps!

It was very helpful and you obviously spent quite a bit of time replying. Thank you.

At this point, based on what you have said, there is a chance the block will time out.  I will patient for a bit and see if that happens.  If it doesn’t work out, I will try contacting the ISP as you suggest  Thank you again.

 

[Admin]

No worries.