Here are the details as requested, Even though this attempt was sent to my kindle address, there are several mentions of GMX in the text.
Hope this is sufficient.
Spoiler:
Starting job: Email Winner Kills All to ????@kindle.com
connect: (u'mail.gmx.com', 587)
connect: (u'mail.gmx.com', 587)
reply: '220 gmx.com (mrgmx003) Nemesis ESMTP Service ready\r\n'
reply: retcode (220); Msg: gmx.com (mrgmx003) Nemesis ESMTP Service ready
connect: gmx.com (mrgmx003) Nemesis ESMTP Service ready
send: 'ehlo Col-PC.localhost\r\n'
reply: '250-gmx.com Hello Col-PC.localhost [203.32.47.228]\r\n'
reply: '250-8BITMIME\r\n'
reply: '250-AUTH LOGIN PLAIN\r\n'
reply: '250-SIZE 69920427\r\n'
reply: '250 STARTTLS\r\n'
reply: retcode (250); Msg: gmx.com Hello Col-PC.localhost [203.32.47.228]
8BITMIME
AUTH LOGIN PLAIN
SIZE 69920427
STARTTLS
send: 'STARTTLS\r\n'
reply: '220 OK\r\n'
reply: retcode (220); Msg: OK
send: 'ehlo Col-PC.localhost\r\n'
reply: '250-gmx.com Hello Col-PC.localhost [203.32.47.228]\r\n'
reply: '250-8BITMIME\r\n'
reply: '250-AUTH LOGIN PLAIN\r\n'
reply: '250 SIZE 69920427\r\n'
reply: retcode (250); Msg: gmx.com Hello Col-PC.localhost [203.32.47.228]
8BITMIME
AUTH LOGIN PLAIN
SIZE 69920427
send: AUTH <censored>
reply: '535 Authentication credentials invalid\r\n'
reply: retcode (535); Msg: Authentication credentials invalid
Sending failed...
Traceback (most recent call last):
File "site-packages\calibre\gui2\email.py", line 44, in run
File "site-packages\calibre\gui2\email.py", line 134, in sendmail
File "site-packages\calibre\utils\smtp.py", line 159, in sendmail
File "site-packages\calibre\utils\smtplib.py", line 648, in login
SMTPAuthenticationError: (535, 'Authentication credentials invalid')
Retrying in 30 seconds...
Waiting 30 seconds before sending, to avoid being marked as spam.
You can control this delay via Preferences->Tweaks
connect: (u'mail.gmx.com', 587)
connect: (u'mail.gmx.com', 587)
reply: '220 gmx.com (mrgmx002) Nemesis ESMTP Service ready\r\n'
reply: retcode (220); Msg: gmx.com (mrgmx002) Nemesis ESMTP Service ready
connect: gmx.com (mrgmx002) Nemesis ESMTP Service ready
send: 'ehlo Col-PC.localhost\r\n'
reply: '250-gmx.com Hello Col-PC.localhost [203.32.47.228]\r\n'
reply: '250-8BITMIME\r\n'
reply: '250-AUTH LOGIN PLAIN\r\n'
reply: '250-SIZE 69920427\r\n'
reply: '250 STARTTLS\r\n'
reply: retcode (250); Msg: gmx.com Hello Col-PC.localhost [203.32.47.228]
8BITMIME
AUTH LOGIN PLAIN
SIZE 69920427
STARTTLS
send: 'STARTTLS\r\n'
reply: '220 OK\r\n'
reply: retcode (220); Msg: OK
send: 'ehlo Col-PC.localhost\r\n'
reply: '250-gmx.com Hello Col-PC.localhost [203.32.47.228]\r\n'
reply: '250-8BITMIME\r\n'
reply: '250-AUTH LOGIN PLAIN\r\n'
reply: '250 SIZE 69920427\r\n'
reply: retcode (250); Msg: gmx.com Hello Col-PC.localhost [203.32.47.228]
8BITMIME
AUTH LOGIN PLAIN
SIZE 69920427
send: AUTH <censored>
reply: '535 Authentication credentials invalid\r\n'
reply: retcode (535); Msg: Authentication credentials invalid
Sending failed...
Traceback (most recent call last):
File "site-packages\calibre\gui2\email.py", line 44, in run
File "site-packages\calibre\gui2\email.py", line 134, in sendmail
File "site-packages\calibre\utils\smtp.py", line 159, in sendmail
File "site-packages\calibre\utils\smtplib.py", line 648, in login
SMTPAuthenticationError: (535, 'Authentication credentials invalid')
Job: "Email Winner Kills All to ????@kindle.com" failed with error:
Traceback (most recent call last):
File "site-packages\calibre\gui2\threaded_jobs.py", line 84, in start_work
File "site-packages\calibre\gui2\email.py", line 101, in __call__
SMTPAuthenticationError: (535, 'Authentication credentials invalid')
Called with args: (u'C:\\Users\\Col\\AppData\\Local\\Temp\\calibre_f jxhaz\\8otmx7caltmpfmt.mobi', u'Winner Kills All - RJ Bailey.mobi', u'????@kindle.com', u'E-book: Winner Kills All', u'Attached, you will find the e-book\n\nWinner Kills All\n\tby RJ Bailey\n\nin the MOBI format.') {u'abort': <threading._Event object at 0x0DEE20B0>, u'log': <calibre.utils.logging.GUILog object at 0x0DEE2170>, u'notifications': <Queue.Queue instance at 0x0AF4C698>}