Gmail SMTP send timeout issues

[sociableorg]

[FIXED]

Hello Calibre gurus - I am having sporadic isssues with gmail smtp send timeout errors. I have Calibre setup to send newsfeeds to my kindle email address. The problem is reproducible in the following scenario:

- If I run 7 jobs (7 separate newsfeeds) one after another (the automation is done by calibre), on any newsfeed download that is more than 2MB (I have verified that 1.8MB files go through no problem), I get an smtp timeout error (logs below for the failed item). Note that if I run individual jobs manually, the smtp timeout error occurs on the bigger files but when I check my gmail 'sent mail folder' I see that the email has been sent successfully and delivered to my kindle device (so basically Calibre logs indicate that an error has occurred because of smtp timeout after 15 mins, but email seems to have been successfully sent). When these jobs are being processed, if I try to 'ping' an website (from dos command line) there is no issues with the ping. However, reaching websites from a web browser on the PC is not possible - looks like the connection to the internet is completely hosed up.

I have already performed the following checks:

- Send Test Mail from inside Preferences->Change Calibre behavior->Gmail settings; Send Test mail succeeds with no problems.
- Changed gmail SMTP settings from TLS/gmail (recommended by calbre FAQ) to SSL/googlemail (in both scenarios I have the same behavior as described above)
- Verified MTU size on PC setting matches my PPPoE connection setting on router (both set to 1492)
- If I use a gmail web client and send the same attachments, I have no issues in sending the files


Any help troubleshooting this issue will be much appreciated!
================================================== =======
connect: (u'smtp.googlemail.com', 465)
reply: '220 mx.google.com ESMTP o3sm21261022wiy.14\r\n'
reply: retcode (220); Msg: mx.google.com ESMTP o3sm21261022wiy.14
connect: mx.google.com ESMTP o3sm21261022wiy.14
send: 'ehlo [192.168.1.107]\r\n'
reply: '250-mx.google.com at your service, [Public IP]\r\n'
reply: '250-SIZE 35882577\r\n'
reply: '250-8BITMIME\r\n'
reply: '250-AUTH LOGIN PLAIN XOAUTH\r\n'
reply: '250 ENHANCEDSTATUSCODES\r\n'
reply: retcode (250); Msg: mx.google.com at your service, [Public IP]
SIZE 35882577
8BITMIME
AUTH LOGIN PLAIN XOAUTH
ENHANCEDSTATUSCODES
send: AUTH <censored>
reply: '235 2.7.0 Accepted\r\n'
reply: retcode (235); Msg: 2.7.0 Accepted
send: u'mail FROM:<xxx.kindle@gmail.com> size=6559578\r\n'
reply: '250 2.1.0 OK o3sm21261022wiy.14\r\n'
reply: retcode (250); Msg: 2.1.0 OK o3sm21261022wiy.14
send: u'rcpt TO:<xxx@kindle.com>\r\n'
reply: '250 2.1.5 OK o3sm21261022wiy.14\r\n'
reply: retcode (250); Msg: 2.1.5 OK o3sm21261022wiy.14
send: 'data\r\n'
reply: '354 Go ahead o3sm21261022wiy.14\r\n'
reply: retcode (354); Msg: Go ahead o3sm21261022wiy.14
data: (354, 'Go ahead o3sm21261022wiy.14')
send: 'Content-Type: multipart/mixed; boundary="===============0410770619=="\r\nMIME-Version: 1.0\r\nSubje...
Sending timed out
Job: "Email The Economist to xxx@kindle.com" failed with error:
Traceback (most recent call last):
File "site-packages\calibre\gui2\threaded_jobs.py", line 83, in start_work
File "site-packages\calibre\gui2\email.py", line 84, in __call__
Exception: Sending email u'News: The Economist' to u'xxx@kindle.com' timed out, aborting

Called with args: (u'c:\\docume~1\\sh~1\\locals~1\\temp\\calibre_0.8 .31_tmp_lwwrrh\\gijvrrcaltmpfmt.mobi', u'The Economist.mobi', u'xxx@kindle.com', u'News: The Economist', u'Attached is the The Economist periodical downloaded by calibre.') {u'notifications': <Queue.Queue instance at 0x07015C38>, u'abort': <threading._Event object at 0x07014A70>, u'log': <calibre.utils.logging.GUILog object at 0x07014B50>}

[kovidgoyal]

The calibre GUI assumes that if an email hasn't been sent in 15 minutes, it is hung. You need to figure out why uploading 2MB is taking more than 15 minutes on your machine.

[sociableorg]

Thanks for the quick response Kovid. First of all - great software!

What I am finding strange is that I have no problems sending the same 5 MB newsfeed attachment via the gmail webtool (i.e. gmail in a webbrowser) - the sending completes in a few seconds. What is different in the SMTP client integrated in Calibre software?

[kovidgoyal]

I have no idea, calibre uses the smtp module from the python standard library.

[sociableorg]

Just figured it out. It was a QoS setting on my router that was messing with the SMTP sessions. I have disabled QoS now and everything works fine. I will have to carefully re-look at the QoS classification rules again if I will turn on QoS. Thanks again for the great software Kovid.