20 second delay between each sent email

Hi, I have been experiencing a strange issue that I suspect may be related to a cPanel upgrade. We use one email account to send out messages to our mailing list. Whenever we send a message, there is exactly a 20 seconds delay between each message. We suspect that maybe cPanel has added some type of spam filter that stops users from sending emails frequently via the same email address... or something similar. We never saw this type of behavior before. Or maybe it is a bug? Please see the following log of 3 sent messages:


[01] 11/2 14:33:22 > AUTH LOGIN
[01] 11/2 14:33:22 334 VXNlcm5hbWU6
[01] 11/2 14:33:22 > ouremail@mail.com[/EMAIL]
[01] 11/2 14:33:22 334 UGFzc3dvcmQ6
[01] 11/2 14:33:22 > **********
[01] 11/2 14:33:22 235 Authentication succeeded
[01] 11/2 14:33:22 > MAIL FROM:
[01] 11/2 14:33:22 250 OK
[01] 11/2 14:33:22 > RCPT TO: [169/9049]
[01] 11/2 14:33:22 250 Accepted
[01] 11/2 14:33:22 > DATA
[01] 11/2 14:33:22 354 Enter message, ending with "." on a line by itself
[01] 11/2 14:33:22 ~ Sending message
[01] 11/2 14:33:22 ~ with ID 
[01] 11/2 14:33:22 ~ To Terri.Ferrell@mtsu.edu[/EMAIL]
[01] 11/2 14:33:22 250 OK id=1ZtGAk-00006V-FQ
[01] 11/2 14:33:22 ~ Stage 3 dispatch done
[01] 11/2 14:33:22 ~ Delay of 0s [00:00:00]
[01] 11/2 14:33:22 > QUIT
[01] 11/2 14:33:22 221 web06.wopsa.se closing connection
[01] 11/2 14:33:22 ~ Stage 4 dispatch done
[01] 11/2 14:33:23 ~ Connected
[01] 11/2 14:33:43 220-web06.wopsa.se ESMTP Exim 4.86 #2 Mon, 02 Nov 2015 15:33:42 +0100
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
[01] 11/2 14:33:43 > EHLO [192.168.0.45]
[01] 11/2 14:33:43 250-web06.example.se Hello cpc66942-cove12-2-0-cust171.3-1.cable.example.net [86.20.60.172]
250-SIZE 52428800
250-8BITMIME
250-PIPELINING
250-AUTH PLAIN LOGIN
250-STARTTLS
250 HELP
[01] 11/2 14:33:43 > AUTH LOGIN
[01] 11/2 14:33:43 334 VXNlcm5hbWU6
[01] 11/2 14:33:43 > ouremail@mail.com[/EMAIL]
[01] 11/2 14:33:43 334 UGFzc3dvcmQ6
[01] 11/2 14:33:43 > **********
[01] 11/2 14:33:43 235 Authentication succeeded
[01] 11/2 14:33:43 > MAIL FROM:
[01] 11/2 14:33:43 250 OK
[01] 11/2 14:33:43 > RCPT TO: [170/9049]
[01] 11/2 14:33:43 250 Accepted
[01] 11/2 14:33:43 > DATA
[01] 11/2 14:33:43 354 Enter message, ending with "." on a line by itself
[01] 11/2 14:33:43 ~ Sending message
[01] 11/2 14:33:43 ~ with ID 
[01] 11/2 14:33:43 ~ To maritess.buslon@example.edu[/EMAIL]
[01] 11/2 14:33:43 250 OK id=1ZtGB5-000097-G1
[01] 11/2 14:33:43 ~ Stage 3 dispatch done
[01] 11/2 14:33:43 ~ Delay of 0s [00:00:00]
[01] 11/2 14:33:43 > QUIT
[01] 11/2 14:33:43 221 web06.wopsa.se closing connection
[01] 11/2 14:33:43 ~ Stage 4 dispatch done
[01] 11/2 14:33:44 ~ Connected
[01] 11/2 14:34:04 220-web06.wopsa.se ESMTP Exim 4.86 #2 Mon, 02 Nov 2015 15:34:03 +0100
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
[01] 11/2 14:34:04 > EHLO [192.168.0.45]
[01] 11/2 14:34:04 250-web06.wopsa.se Hello cpc66942-cove12-2-0-cust171.3-1.cable.domain.net [86.20.60.172]
250-SIZE 52428800
250-8BITMIME
250-PIPELINING
250-AUTH PLAIN LOGIN
250-STARTTLS
250 HELP
[01] 11/2 14:34:04 > AUTH LOGIN
[01] 11/2 14:34:04 334 VXNlcm5hbWU6
[01] 11/2 14:34:04 > ouremail@mail.com[/EMAIL]
[01] 11/2 14:34:04 334 UGFzc3dvcmQ6
[01] 11/2 14:34:04 > **********
[01] 11/2 14:34:04 235 Authentication succeeded
[01] 11/2 14:34:04 > MAIL FROM:
[01] 11/2 14:34:04 250 OK
[01] 11/2 14:34:04 > RCPT TO: [171/9049]
[01] 11/2 14:34:04 250 Accepted
[01] 11/2 14:34:04 > DATA
[01] 11/2 14:34:04 354 Enter message, ending with "." on a line by itself
[01] 11/2 14:34:04 ~ Sending message
[01] 11/2 14:34:04 ~ with ID <4ZYVUZLI-EA2-6IOL-TTHU-5IH4S8ZO4IC7@example.com>
[01] 11/2 14:34:04 ~ To jones.l@example.edu[/EMAIL]
[01] 11/2 14:34:05 250 OK id=1ZtGBQ-0000B7-Dv
[01] 11/2 14:34:05 ~ Stage 3 dispatch done
[01] 11/2 14:34:05 ~ Delay of 0s [00:00:00]
[01] 11/2 14:34:05 > QUIT
[01] 11/2 14:34:05 221 web06.domain.se closing connection
[01] 11/2 14:34:05 ~ Stage 4 dispatch done
[01] 11/2 14:34:05 ~ Connected
[01] 11/2 14:34:25 220-web06.wopsa.se ESMTP Exim 4.86 #2 Mon, 02 Nov 2015 15:34:25 +0100
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
[01] 11/2 14:34:25 > EHLO [192.168.0.45]
[01] 11/2 14:34:25 250-web06.wopsa.se Hello cpc66942-cove12-2-0-cust171.3-1.cable.example.net [86.20.60.172]

As you can see, there is exactly a 20 second delay: [01] 11/2 14:33:23 ~ Connected [01] 11/2 14:33:43 220-web06.wopsa.se ESMTP Exim 4.86 #2 Mon, 02 Nov 2015 15:33:42 +0100 Do anyone know what the deal is?

Infopro

November 04, 2015 16:16

This may be helpful to you: Greylisting - Documentation - cPanel Documentation

Mark Donne

November 12, 2015 08:59

Hi Alyson We were getting a similar issue and it was down to the latest upgrade (11.52). cPanel have introduced a delay to all incoming SMTP transactions as detailed here 11.52 Release Notes - Documentation - cPanel Documentation

20 second delay between each sent email

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