Dear collegues,
my administration writes one(!) email with more than 3000 receipients
in the envelope. (Please, no discussion about the sense of this. Period.)
Receiving that mail takes about 2 two hours.
Delivering that mail is done very quick, as usual.
I started debugging this and I recognized that
after every "RCPT TO" it took a sucessive increasing time
until the "250 Accepted" was answered.
At the beginning this was a 10th of a second.
After 1000 recipients there was a delay of ~one second
after the 2000th recipients this delay increased smoothly
to 2 secends ofter each rcpt-to
I threw away all my bells and whistles in the exim config,
but no success.
So I started "strace" to see whats happening:
At the beginning I see
18:35:36.048265 read(7, "RCPT TO:<AAAA@BBBBB>\r\n", 8191) = 45
18:35:36.063187 alarm(0) = 300
18:35:36.063233 rt_sigaction(SIGALRM, {sa_handler=0x55bc6f392180, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7f8eff4d9730}, NULL, 8) = 0
18:35:36.140936 socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 9
see the nearly zero difference between the RCPT line and the socket line
After ~1000 recipients I have:
18:40:51.670874 read(7, "RCPT TO:<XXXXX@YYYYYY>\r\n", 8191) = 43
18:40:51.685450 alarm(0) = 300
18:40:51.685538 rt_sigaction(SIGALRM, {sa_handler=0x55bc6f392180, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7f8eff4d9730}, NULL, 8) = 0
18:40:52.277971 socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 9
so half a second between the rcpt line and the socket line
After ~2000 recipients:
19:06:28.229652 read(7, "RCPT TO:<ZZZZ@ZZZZ>\r\n", 8191) = 29
19:06:28.244041 alarm(0) = 300
19:06:28.244253 rt_sigaction(SIGALRM, {sa_handler=0x55bc6f392180, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7f8eff4d9730}, NULL, 8) = 0
19:06:29.776217 socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 9
about 1.5 seconds between rcpt and the socket line
There are no dropped lines between the RCPT line until the socket line in the strace output
Any ideas what's happening here ?
(testing was done with "swaks" talking directly to the exim)
Regards, Olaf
--
Karlsruher Institut für Technologie (KIT)
Steinbuch Centre for Computing (SCC)
Dipl.-Geophys. Olaf Hopp
Zirkel 2
Gebäude 20.21, Raum 316
76131 Karlsruhe
Telefon: +49 721 608-48009
E-Mail: Olaf.Hopp@???
Web:
www.scc.kit.edu
Sitz der Körperschaft:
Kaiserstraße 12, 76131 Karlsruhe
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