1
Post 8251 Update Issue
Problem reported by Rod Strumbel - 1/23/2023 at 10:49 AM
Resolved
Have several customers reporting that THEIR customers are receiving the message:
554 Maximum hop count exceeded. Possible loop.

When trying to send email to them (so this is INBOUND to our client accounts where the sender is seeing this message coming from our server).

This was NOT happening before this past weekends update to 8251.
Literally, not at all, I went back a full week of logs and that "554 Max..." doesn't appear in them at all.

Anyone run into this ?

Fixes ?


9 Replies

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0
Andrea Free Replied
Employee Post
Hi Rod, 

You'll find a Max Hop Count setting in Protocol settings, on the SMTP In tab. What is yours set to?

In Build 8250, we fixed the following issue: 
Fixed: An issue where more than one message sent during an single SMTP session skips some steps.

It's possible that you should have been receiving this error all along, but didn't because SmarterMail was skipping some steps with those deliveries. 

If your Max Hop Count setting is really high, and if you're not sure it's working properly, it may be best to open a support ticket. Our support technicians can look at the SMTP logs and see what's happening during the delivery. 

Andrea Free
SmarterTools Inc.
877-357-6278

www.smartertools.com

0
Rod Strumbel Replied
Thank you Andrea.

I have opened a ticket and Tony S is currently looking into it.

Max hop count setting is only at 30, but it really shouldn't need to be any higher than that I wouldn't think depending on what all goes into being counted as a "hop" though I guess.
1
Rod Strumbel Replied
We have discovered an "interesting" issue.  Once I have proof of what is causing this, I will post more info.  Thank you Tony for pointing us in what I believe is the right direction.

I will say... the sky is not falling.   For MOST people this will likely never be an issue.  So worry not.
0
Andrea Free Replied
Employee Post
Thanks for the update, Rod! I look forward to hearing more when the cause has been discovered! 

Andrea Free
SmarterTools Inc.
877-357-6278

www.smartertools.com

0
Rod Strumbel Replied
Well... here is what is going on... it also is the cause of the issue I have been reporting FOR YEARS about multiple messages having the same Message Id in our SMTP logs.

We have an Antivirus/Antispam box in front of our SmarterMail server.

This box communicates via a batch sending mode that for MOST mail servers is not an issue.
So it basically:
Message --> AVAS Box (process for virus / spam)--> Temp Store message if ok
At regular (and highly frequent) intervals gather up all pending messages to send and queue them up

When communicating with the SmarterMail server that does the following:
CONNECT TO SMARTERMAIL
-- SEND MESSAGE #1
-- ISSUE RSET
-- SEND MESSAGE #2
-- ISSUE RSET
--continue until done with pending messages
DISCONNECT FROM SMARTERMAIL

What SmarterMail does/sees
SMTP-IN CONNECTION ESTABLISHED (Assign Message ID)
-- GET MESSAGE (Apply Message ID)
-- --  Perform size and hop count evaluations for Message ID:  End processing if necessary and send notices
-- GET MESSAGE (Apply the SAME MESSAGE ID)
-- --  Perform size and hop count evaluations for Message ID:  End processing if necessary and send notices
-- repeat until...
DISCONNECTED

So ALL of the messages sent in that batch from the front-end server end up getting the same Message Id.

This does AT LEAST 2 things:
1) It severely throws off the HOP COUNT processing since this appears to be done per Message Id instead of per actual email.

2) It really screws up the SMTP logs in that all those messages now have the same message Id stamped into them... so if you do standard message analysis in the logs:  search for issue, get message id, then lookup message id for that message details... you get ALL those messages returned... not really very helpful.

The hop-count issue started after the upgrade to 8251.  Why?  Still waiting on an answer for that.  I'm guessing it wasn't being "enforced" prior... or it was being calculated differently...but that is just a guess.

The hop-count currently is a BIG issue as it prevents delivery of the message and any subsequent messages in that batch that occur after the HOP COUNT EXCEEDED maximum value is hit.  
As a temporary "patch" we have upped our hop-count allowed to a ridiculous number.  But that is only temporary as we could potentially get a forwarding loop in there that could spiral out of control.

Still waiting on a solution from SmarterMail for this, have to say Tony S has been very responsive and assisted in identifying the problem.


0
Zach Sylvester Replied
Employee Post
Hey Rod, 

Thanks for the reply and for giving us some information about this issue. 
It looks like I've been able to reproduce this issue. 
Please see the log below. 
[2023.01.24] 15:55:45.792 [ip address][50367485] rsp: 220 mail.recipient mail server.com  Tue, 24 Jan 2023 22:55:45 +0000 UTC
[2023.01.24] 15:55:45.792 [ip address][50367485] connected at 1/24/2023 3:55:45 PM
[2023.01.24] 15:55:45.818 [ip address][50367485] Country code: Unknown
[2023.01.24] 15:55:45.818 [ip address][50367485] IP in whitelist
[2023.01.24] 15:55:45.818 [ip address][50367485] IP in authentication bypass
[2023.01.24] 15:55:45.819 [ip address][50367485] cmd: EHLO mail.Sending server.com
[2023.01.24] 15:55:45.820 [ip address][50367485] rsp: 250-mail.recipient mail server.com Hello [ip address]250-SIZE 699050666250-AUTH CRAM-MD5250-STARTTLS250-8BITMIME250-DSN250 OK
[2023.01.24] 15:55:45.821 [ip address][50367485] cmd: STARTTLS
[2023.01.24] 15:55:45.821 [ip address][50367485] rsp: 220 Start TLS negotiation
[2023.01.24] 15:55:45.830 [ip address][50367485] cmd: EHLO mail.Sending server.com
[2023.01.24] 15:55:45.831 [ip address][50367485] rsp: 250-mail.recipient mail server.com Hello [ip address]250-SIZE 699050666250-AUTH LOGIN CRAM-MD5250-8BITMIME250-DSN250 OK
[2023.01.24] 15:55:45.832 [ip address][50367485] cmd: MAIL FROM:<from@emailaddress.com> SIZE=6642 BODY=7BIT
[2023.01.24] 15:55:45.834 [ip address][50367485] senderEmail(1): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:45.834 [ip address][50367485] rsp: 250 OK <from@emailaddress.com> Sender ok
[2023.01.24] 15:55:45.834 [ip address][50367485] Sender accepted. Weight: 0. 
[2023.01.24] 15:55:45.834 [ip address][50367485] cmd: RCPT TO:<to@emailaddress.com>
[2023.01.24] 15:55:45.835 [ip address][50367485] rsp: 250 OK <to@emailaddress.com> Recipient ok
[2023.01.24] 15:55:45.836 [ip address][50367485] cmd: DATA
[2023.01.24] 15:55:45.836 [ip address][50367485] Performing PTR host name lookup for ip address
[2023.01.24] 15:55:45.861 [ip address][50367485] PTR host name for ip address resolved as UnknownHost
[2023.01.24] 15:55:45.863 [ip address][50367485] rsp: 354 Start mail input; end with <CRLF>.<CRLF>
[2023.01.24] 15:55:45.864 [ip address][50367485] senderEmail(2): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:45.865 [ip address][50367485] DMARC Results: Skipped (DMARC Disabled), Reason: Unknown, Reject? False
[2023.01.24] 15:55:45.865 [ip address][50367485] rsp: 250 OK
[2023.01.24] 15:55:45.866 [ip address][50367485] Received message size: 2216 bytes
[2023.01.24] 15:55:46.117 [ip address][50367485] Successfully wrote to the HDR file. (c:\SmarterMail\Spool\SubSpool12\-1255544858131.hdr)
[2023.01.24] 15:55:46.117 [ip address][50367485] Data transfer succeeded, writing mail to -1255544858131.eml (MessageID: <3e5e761b-5cb1-47ed-a68d-c95ce7bb6fd2@dev-exch2019.Sending server.com>)
[2023.01.24] 15:55:46.117 [ip address][50367485] cmd: MAIL FROM:<from@emailaddress.com> SIZE=6633 BODY=7BIT
[2023.01.24] 15:55:46.119 [ip address][50367485] senderEmail(1): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.119 [ip address][50367485] rsp: 250 OK <from@emailaddress.com> Sender ok
[2023.01.24] 15:55:46.119 [ip address][50367485] Sender accepted. Weight: 0. 
[2023.01.24] 15:55:46.123 [ip address][50367485] cmd: RCPT TO:<to@emailaddress.com>
[2023.01.24] 15:55:46.123 [ip address][50367485] rsp: 250 OK <to@emailaddress.com> Recipient ok
[2023.01.24] 15:55:46.124 [ip address][50367485] cmd: DATA
[2023.01.24] 15:55:46.124 [ip address][50367485] Performing PTR host name lookup for ip address
[2023.01.24] 15:55:46.150 [ip address][50367485] PTR host name for ip address resolved as UnknownHost
[2023.01.24] 15:55:46.153 [ip address][50367485] rsp: 354 Start mail input; end with <CRLF>.<CRLF>
[2023.01.24] 15:55:46.154 [ip address][50367485] senderEmail(2): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.154 [ip address][50367485] senderEmail(2): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.154 [ip address][50367485] DMARC Results: Skipped (DMARC Disabled), Reason: Unknown, Reject? False
[2023.01.24] 15:55:46.154 [ip address][50367485] rsp: 250 OK
[2023.01.24] 15:55:46.155 [ip address][50367485] Received message size: 2216 bytes
[2023.01.24] 15:55:46.406 [ip address][50367485] Successfully wrote to the HDR file. (c:\SmarterMail\Spool\SubSpool13\-1255544858132.hdr)
[2023.01.24] 15:55:46.406 [ip address][50367485] Data transfer succeeded, writing mail to -1255544858132.eml (MessageID: <178be9ec-7ab9-43c4-bc21-73dd68798df4@dev-exch2019.Sending server.com>)
[2023.01.24] 15:55:46.406 [ip address][50367485] cmd: MAIL FROM:<from@emailaddress.com> SIZE=6628 BODY=7BIT
[2023.01.24] 15:55:46.408 [ip address][50367485] senderEmail(1): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.408 [ip address][50367485] rsp: 250 OK <from@emailaddress.com> Sender ok
[2023.01.24] 15:55:46.408 [ip address][50367485] Sender accepted. Weight: 0. 
[2023.01.24] 15:55:46.409 [ip address][50367485] cmd: RCPT TO:<to@emailaddress.com>
[2023.01.24] 15:55:46.409 [ip address][50367485] rsp: 250 OK <to@emailaddress.com> Recipient ok
[2023.01.24] 15:55:46.410 [ip address][50367485] cmd: DATA
[2023.01.24] 15:55:46.410 [ip address][50367485] Performing PTR host name lookup for ip address
[2023.01.24] 15:55:46.438 [ip address][50367485] PTR host name for ip address resolved as UnknownHost
[2023.01.24] 15:55:46.440 [ip address][50367485] rsp: 354 Start mail input; end with <CRLF>.<CRLF>
[2023.01.24] 15:55:46.441 [ip address][50367485] senderEmail(2): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.441 [ip address][50367485] senderEmail(2): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.441 [ip address][50367485] senderEmail(2): from@emailaddress.com parsed using: <from@emailaddress.com>
[2023.01.24] 15:55:46.442 [ip address][50367485] Successfully wrote to the HDR file. (c:\SmarterMail\Spool\SubSpool14\-1255544858133.hdr)
[2023.01.24] 15:55:46.442 [ip address][50367485] data transfer failed. 
[2023.01.24] 15:55:46.442 [ip address][50367485] rsp: 554 Maximum hop count exceeded. Possible loop.
[2023.01.24] 15:55:46.442 [ip address][50367485] disconnected at 1/24/2023 3:55:46 PM


Can you confirm if your log looks the same or at least similar? 

Kind Regards, 
Zach Sylvester
Technical Support Specialist
SmarterTools Inc.
(877) 357-6278
www.smartertools.com
0
Zach Sylvester Replied
Employee Post
Hey Guys, 

I talked to Rod and our logs are similar. I have submitted this issue to development so I'm going to update this thread to being fixed. 

Kind Regards, 
Zach Sylvester
Technical Support Specialist
SmarterTools Inc.
(877) 357-6278
www.smartertools.com
0
Kyle Kerst Replied
Employee Post
I just wanted to follow up here to let you know this (hop count error using RSET) has been resolved and confirmed in-house at this point. This fix should be available in our next beta release.
Kyle Kerst
Technical Support Specialist
SmarterTools Inc.
(877) 357-6278
www.smartertools.com
0
Rod Strumbel Replied
Well... the powers that be won't let me load a beta into our client customer server, so guess I have to wait for the next official release.

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