Exception: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.
Problem reported by Patrick Hedgepath - December 18, 2018 at 11:25 AM
Submitted
We are having an issue being reported by a client where whenever email is sent to their parent company that has an attachment it is not being delivered. I tried a test of this myself and I see the same problem in the logs. From what I can tell the issue is coming from the receiving mail server closing the connection. Am I reading this wrong? I sent a small text file as a test and that went right through but I sent a 5mb pdf file it doesn't make it. Here is the log entry thus far.

[2018.12.18] 13:01:16 [44290] Delivery started for webmaster@pegweb.com at 1:01:16 PM
[2018.12.18] 13:01:26 [44290] Added to SpamCheckQueue (0 queued; 7/30 processing)
[2018.12.18] 13:01:27 [44290] Starting Spam Checks.
[2018.12.18] 13:01:27 [44290] Skipping spam checks: User authenticated
[2018.12.18] 13:01:27 [44290] Spam Checks completed.
[2018.12.18] 13:01:27 [44290] Removed from SpamCheckQueue (1 queued or processing)
[2018.12.18] 13:01:31 [44290] Added to RemoteDeliveryQueue (1 queued; 39/50 processing)
[2018.12.18] 13:01:31 [44290] Sending remote mail for webmaster@pegweb.com
[2018.12.18] 13:01:31 [44290] Sending remote mail to: jt@maxpack.com
[2018.12.18] 13:01:31 [44290] Initiating connection to 162.155.96.250
[2018.12.18] 13:01:31 [44290] Connecting to 162.155.96.250:25 (Id: 1)
[2018.12.18] 13:01:31 [44290] Connection to 162.155.96.250:25 from 131.153.100.52:51208 succeeded (Id: 1)
[2018.12.18] 13:01:31 [44290] RSP: 220 mail.maxpack.com Microsoft ESMTP MAIL Service ready at Tue, 18 Dec 2018 13:01:29 -0500
[2018.12.18] 13:01:31 [44290] CMD: EHLO mail.pegweb.net
[2018.12.18] 13:01:31 [44290] RSP: 250-mail.maxpack.com Hello [131.153.100.52]
[2018.12.18] 13:01:31 [44290] RSP: 250-SIZE
[2018.12.18] 13:01:31 [44290] RSP: 250-PIPELINING
[2018.12.18] 13:01:31 [44290] RSP: 250-DSN
[2018.12.18] 13:01:31 [44290] RSP: 250-ENHANCEDSTATUSCODES
[2018.12.18] 13:01:31 [44290] RSP: 250-STARTTLS
[2018.12.18] 13:01:31 [44290] RSP: 250-AUTH LOGIN
[2018.12.18] 13:01:31 [44290] RSP: 250-8BITMIME
[2018.12.18] 13:01:31 [44290] RSP: 250-BINARYMIME
[2018.12.18] 13:01:31 [44290] RSP: 250 CHUNKING
[2018.12.18] 13:01:31 [44290] CMD: STARTTLS
[2018.12.18] 13:01:31 [44290] RSP: 220 2.0.0 SMTP server ready
[2018.12.18] 13:01:31 [44290] CMD: EHLO mail.pegweb.net
[2018.12.18] 13:01:31 [44290] RSP: 250-mail.maxpack.com Hello [131.153.100.52]
[2018.12.18] 13:01:31 [44290] RSP: 250-SIZE
[2018.12.18] 13:01:31 [44290] RSP: 250-PIPELINING
[2018.12.18] 13:01:31 [44290] RSP: 250-DSN
[2018.12.18] 13:01:31 [44290] RSP: 250-ENHANCEDSTATUSCODES
[2018.12.18] 13:01:31 [44290] RSP: 250-AUTH LOGIN
[2018.12.18] 13:01:31 [44290] RSP: 250-8BITMIME
[2018.12.18] 13:01:31 [44290] RSP: 250-BINARYMIME
[2018.12.18] 13:01:31 [44290] RSP: 250 CHUNKING
[2018.12.18] 13:01:31 [44290] CMD: MAIL FROM:<webmaster@pegweb.com> SIZE=6743338
[2018.12.18] 13:01:31 [44290] RSP: 250 2.1.0 Sender OK
[2018.12.18] 13:01:31 [44290] CMD: RCPT TO:<jt@maxpack.com>
[2018.12.18] 13:01:32 [44290] RSP: 250 2.1.5 Recipient OK
[2018.12.18] 13:01:32 [44290] CMD: DATA
[2018.12.18] 13:01:32 [44290] RSP: 354 Start mail input; end with <CRLF>.<CRLF>
[2018.12.18] 13:12:12 [44290] Exception: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.
[2018.12.18]    at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)   at System.Net.Security._SslStream.StartWriting(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)   at System.Net.Security._SslStream.ProcessWrite(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)   at System.Net.Security.SslStream.Write(Byte[] buffer)   at RelayServer.Clients.SMTP.ClientConnectionSync.SendLine(String line, Encoding enc)   at RelayServer.Clients.SMTP.SmtpClientSession.SendLine(String #a8, Encoding #TNi)   at RelayServer.Clients.SMTP.SmtpClientSession.SendData(StreamReader #bJ)   at RelayServer.Clients.SMTP.SmtpClientSession.SendData()   at RelayServer.Clients.SMTP.SmtpClientSession.#OI()   at RelayServer.Clients.SMTP.SmtpClientSession.StartProcessing()13:12:12 [44290] Sending remote mail to: jt@maxpack.com
[2018.12.18] 13:12:12 [44290] Initiating connection to 162.155.96.250
[2018.12.18] 13:12:12 [44290] Connecting to 162.155.96.250:25 (Id: 2)
[2018.12.18] 13:12:12 [44290] Connection to 162.155.96.250:25 from 131.153.100.52:65009 succeeded (Id: 2)
[2018.12.18] 13:12:12 [44290] RSP: 220 mail.maxpack.com Microsoft ESMTP MAIL Service ready at Tue, 18 Dec 2018 13:12:11 -0500
[2018.12.18] 13:12:12 [44290] CMD: EHLO mail.pegweb.net
[2018.12.18] 13:12:12 [44290] RSP: 250-mail.maxpack.com Hello [131.153.100.52]
[2018.12.18] 13:12:12 [44290] RSP: 250-SIZE
[2018.12.18] 13:12:12 [44290] RSP: 250-PIPELINING
[2018.12.18] 13:12:12 [44290] RSP: 250-DSN
[2018.12.18] 13:12:12 [44290] RSP: 250-ENHANCEDSTATUSCODES
[2018.12.18] 13:12:12 [44290] RSP: 250-STARTTLS
[2018.12.18] 13:12:12 [44290] RSP: 250-AUTH LOGIN
[2018.12.18] 13:12:12 [44290] RSP: 250-8BITMIME
[2018.12.18] 13:12:12 [44290] RSP: 250-BINARYMIME
[2018.12.18] 13:12:12 [44290] RSP: 250 CHUNKING
[2018.12.18] 13:12:12 [44290] CMD: STARTTLS
[2018.12.18] 13:12:12 [44290] RSP: 220 2.0.0 SMTP server ready
[2018.12.18] 13:12:12 [44290] CMD: EHLO mail.pegweb.net
[2018.12.18] 13:12:12 [44290] RSP: 250-mail.maxpack.com Hello [131.153.100.52]
[2018.12.18] 13:12:12 [44290] RSP: 250-SIZE
[2018.12.18] 13:12:12 [44290] RSP: 250-PIPELINING
[2018.12.18] 13:12:12 [44290] RSP: 250-DSN
[2018.12.18] 13:12:12 [44290] RSP: 250-ENHANCEDSTATUSCODES
[2018.12.18] 13:12:12 [44290] RSP: 250-AUTH LOGIN
[2018.12.18] 13:12:12 [44290] RSP: 250-8BITMIME
[2018.12.18] 13:12:12 [44290] RSP: 250-BINARYMIME
[2018.12.18] 13:12:12 [44290] RSP: 250 CHUNKING
[2018.12.18] 13:12:12 [44290] CMD: MAIL FROM:<webmaster@pegweb.com> SIZE=6743338
[2018.12.18] 13:12:12 [44290] RSP: 250 2.1.0 Sender OK
[2018.12.18] 13:12:12 [44290] CMD: RCPT TO:<jt@maxpack.com>
[2018.12.18] 13:12:13 [44290] RSP: 250 2.1.5 Recipient OK
[2018.12.18] 13:12:13 [44290] CMD: DATA
[2018.12.18] 13:12:13 [44290] RSP: 354 Start mail input; end with <CRLF>.<CRLF>
[2018.12.18] 13:17:22 [44290] Delivery started for webmaster@pegweb.com at 1:17:22 PM
[2018.12.18] 13:17:25 [44290] Added to SpamCheckQueue (0 queued; 3/30 processing)
[2018.12.18] 13:17:25 [44290] Starting Spam Checks.
[2018.12.18] 13:17:25 [44290] Skipping spam checks: User authenticated
[2018.12.18] 13:17:25 [44290] Spam Checks completed.
[2018.12.18] 13:17:25 [44290] Removed from SpamCheckQueue (2 queued or processing)
[2018.12.18] 13:17:28 [44290] Added to RemoteDeliveryQueue (1 queued; 12/50 processing)
[2018.12.18] 13:17:28 [44290] Sending remote mail for webmaster@pegweb.com
[2018.12.18] 13:17:28 [44290] Sending remote mail to: jt@maxpack.com
[2018.12.18] 13:17:28 [44290] Initiating connection to 162.155.96.250
[2018.12.18] 13:17:28 [44290] Connecting to 162.155.96.250:25 (Id: 1)
[2018.12.18] 13:17:29 [44290] Connection to 162.155.96.250:25 from 131.153.100.52:64633 succeeded (Id: 1)
[2018.12.18] 13:17:29 [44290] RSP: 220 mail.maxpack.com Microsoft ESMTP MAIL Service ready at Tue, 18 Dec 2018 13:17:27 -0500
[2018.12.18] 13:17:29 [44290] CMD: EHLO mail.pegweb.net
[2018.12.18] 13:17:29 [44290] RSP: 250-mail.maxpack.com Hello [131.153.100.52]
[2018.12.18] 13:17:29 [44290] RSP: 250-SIZE
[2018.12.18] 13:17:29 [44290] RSP: 250-PIPELINING
[2018.12.18] 13:17:29 [44290] RSP: 250-DSN
[2018.12.18] 13:17:29 [44290] RSP: 250-ENHANCEDSTATUSCODES
[2018.12.18] 13:17:29 [44290] RSP: 250-STARTTLS
[2018.12.18] 13:17:29 [44290] RSP: 250-AUTH LOGIN
[2018.12.18] 13:17:29 [44290] RSP: 250-8BITMIME
[2018.12.18] 13:17:29 [44290] RSP: 250-BINARYMIME
[2018.12.18] 13:17:29 [44290] RSP: 250 CHUNKING
[2018.12.18] 13:17:29 [44290] CMD: STARTTLS
[2018.12.18] 13:17:29 [44290] RSP: 220 2.0.0 SMTP server ready
[2018.12.18] 13:17:29 [44290] CMD: EHLO mail.pegweb.net
[2018.12.18] 13:17:29 [44290] RSP: 250-mail.maxpack.com Hello [131.153.100.52]
[2018.12.18] 13:17:29 [44290] RSP: 250-SIZE
[2018.12.18] 13:17:29 [44290] RSP: 250-PIPELINING
[2018.12.18] 13:17:29 [44290] RSP: 250-DSN
[2018.12.18] 13:17:29 [44290] RSP: 250-ENHANCEDSTATUSCODES
[2018.12.18] 13:17:29 [44290] RSP: 250-AUTH LOGIN
[2018.12.18] 13:17:29 [44290] RSP: 250-8BITMIME
[2018.12.18] 13:17:29 [44290] RSP: 250-BINARYMIME
[2018.12.18] 13:17:29 [44290] RSP: 250 CHUNKING
[2018.12.18] 13:17:29 [44290] CMD: MAIL FROM:<webmaster@pegweb.com> SIZE=6743338
[2018.12.18] 13:17:29 [44290] RSP: 250 2.1.0 Sender OK
[2018.12.18] 13:17:29 [44290] CMD: RCPT TO:<jt@maxpack.com>
[2018.12.18] 13:17:29 [44290] RSP: 250 2.1.5 Recipient OK
[2018.12.18] 13:17:29 [44290] CMD: DATA
[2018.12.18] 13:17:29 [44290] RSP: 354 Start mail input; end with <CRLF>.<CRLF>
[2018.12.18] 13:17:29 [44290] Exception: The process cannot access the file 'c:\SmarterMail\Spool\SubSpool3\-1963173244290.eml' because it is being used by another process.
[2018.12.18]    at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy)   at System.IO.FileStream..ctor(String path, FileMode mode)   at RelayServer.Clients.SMTP.SmtpClientSession.SendData()   at RelayServer.Clients.SMTP.SmtpClientSession.#OI()   at RelayServer.Clients.SMTP.SmtpClientSession.StartProcessing()13:17:29 [44290] CMD: QUIT
[2018.12.18] 13:17:34 [44290] Removed from RemoteDeliveryQueue (8 queued or processing)
[2018.12.18] 13:21:24 [44290] Delivery started for webmaster@pegweb.com at 1:21:24 PM
[2018.12.18] 13:21:28 [44290] Added to SpamCheckQueue (0 queued; 3/30 processing)
[2018.12.18] 13:21:28 [44290] Starting Spam Checks.
[2018.12.18] 13:21:28 [44290] Skipping spam checks: User authenticated
[2018.12.18] 13:21:28 [44290] Spam Checks completed.
[2018.12.18] 13:21:28 [44290] Removed from SpamCheckQueue (2 queued or processing)


3 Replies

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0
Patrick Hedgepath Replied
The bounce I finally get back shows the following 

Could not deliver message to the following recipient(s):

Failed Recipient: jt@maxpack.com
Reason: Remote host said: 601 Attempted to send the message to the following IPs:
        162.155.96.250, 162.155.96.250
0
Scarab Replied
Patrick,

We've been getting a lot of these as well lately. It is indeed the other side unceremoniously dropping the connection. In almost all of the cases for SMTP that I've run to ground it has been either a Sonic Firewall or Barracuda Essentials & Sentinel on the recipient's end that is doing this.

Basically, something about the email attachment is triggering their Zero Hour Anti-Spam/Phishing/AntiVirus settings (in our case it seems to happen with PDFs, especially PDF version format 1.7 or earlier). The client could try putting the attachment in a compressed archive (like a .zip) or upload the attachment to Smartermail File Storage and send the link to the file instead to get around it, otherwise it would be something that would have to be fixed on the recipient's side.

(We also see a lot of cases with this happening in IMAP and POP client-side, similar error and is almost always an Anti-Virus product on the client's computer.)
0
Patrick Hedgepath Replied
I tried sending the same file zipped but no luck. It does the same thing :(

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