День добрый! толкнулся с такой проблемой. С нашего сервера на внешний адрес почты приходят письма такого содержания "SMTP error: 552 5.3.4 Message size exceeds fixed limit". Причем по словам получателя нам он сообщения большго размера отсылал минимум месяц назад, и в логах от него писем единицы. Делаю cat mail.log| grep user@yandex.ru
Dec 11 12:12:07 mail amavis[6227]: (06227-18) Passed CLEAN, MYNETS LOCAL [127.0.0.1] [127.0.0.1] <> -> <user@yandex.ru>, Message-ID: <20121211081206.21C85742AB8@mail.bss-nn.ru>, mail_id: yqkR9WsZVmgH, Hits: -10.778, size: 3587, queued_as: AC459742ABA, 530 ms
Dec 11 12:12:07 mail postfix/smtp[6374]: 21C85742AB8: to=<user@yandex.ru>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.6, delays=1.1/0/0/0.53, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as AC459742ABA)
Dec 11 12:12:08 mail postfix/smtp[6350]: AC459742ABA: to=<user@yandex.ru>, relay=mx.yandex.ru[213.180.193.89]:25, delay=0.96, delays=0/0.01/0.1/0.85, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued on mxfront2h.mail.yandex.net as CQ3aAxqE-CQ34rkah)
Dec 11 12:24:07 mail amavis[6899]: (06899-14) Passed CLEAN, MYNETS LOCAL [127.0.0.1] [127.0.0.1] <> -> <user@yandex.ru>, Message-ID: <20121211082405.B9B78742A95@mail.bss-nn.ru>, mail_id: N91PCvy6Ew1O, Hits: -10.778, size: 3587, queued_as: 3A6CE742AC1, 440 ms
Dec 11 12:24:07 mail postfix/smtp[6985]: B9B78742A95: to=<user@yandex.ru>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.5, delays=1.1/0/0/0.44, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 3A6CE742AC1)
Dec 11 12:24:08 mail postfix/smtp[6406]: 3A6CE742AC1: to=<user@yandex.ru>, relay=mx.yandex.ru[213.180.204.89]:25, delay=1, delays=0/0/0.1/0.9, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued on mxfront22.mail.yandex.net as OPZi8ESv-OPZaLDZo)
Dec 11 12:36:06 mail amavis[7592]: (07592-06) Passed CLEAN, MYNETS LOCAL [127.0.0.1] [127.0.0.1] <> -> <user@yandex.ru>, Message-ID: <20121211083605.5CD84742AC2@mail.bss-nn.ru>, mail_id: Rzt+OfjyQ8c9, Hits: -10.778, size: 3587, queued_as: E6CBB742AC3, 527 ms
Dec 11 12:36:06 mail postfix/smtp[7502]: 5CD84742AC2: to=<user@yandex.ru>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.6, delays=1.1/0/0/0.53, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as E6CBB742AC3)
Dec 11 12:36:07 mail postfix/smtp[7557]: E6CBB742AC3: to=<user@yandex.ru>, relay=mx.yandex.ru[87.250.250.89]:25, delay=0.83, delays=0/0/0.11/0.71, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued on mxfront31.mail.yandex.net as aPK4o0UX-aPK8hcJw)
Dec 11 12:48:06 mail amavis[8032]: (08032-16) Passed CLEAN, MYNETS LOCAL [127.0.0.1] [127.0.0.1] <> -> <user@yandex.ru>, Message-ID: <20121211084804.CB1B3742ACA@mail.bss-nn.ru>, mail_id: WgqJQ3Ckm-NN, Hits: -10.778, size: 3587, queued_as: 536CE742AC8, 470 ms
Dec 11 12:48:06 mail postfix/smtp[8160]: CB1B3742ACA: to=<user@yandex.ru>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.6, delays=1.1/0/0/0.47, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 536CE742AC8)
Dec 11 12:48:07 mail postfix/smtp[7691]: 536CE742AC8: to=<user@yandex.ru>, relay=mx.yandex.ru[93.158.134.89]:25, delay=0.72, delays=0/0.01/0.11/0.6, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued on mxfront3m.mail.yandex.net as mOg4fEAF-mOg4eRoE)
Dec 11 12:49:08 mail amavis[8207]: (08207-05) Passed CLEAN, MYNETS/MYUSERS LOCAL [192.168.0.79] [192.168.0.79] <yar@bss-nn.ru> -> <user@yandex.ru>, Message-ID: <50C6F394.4030905@bss-nn.ru>, mail_id: h7rb0xtZ0peL, Hits: -111.899, size: 8103, queued_as: 52386742ACA, 384 ms
Dec 11 12:49:08 mail postfix/smtp[8160]: CBC23742AC9: to=<user@yandex.ru>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.6, delays=1.2/0/0/0.38, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 52386742ACA)
Dec 11 12:49:10 mail postfix/smtp[7691]: 52386742ACA: to=<user@yandex.ru>, relay=mx.yandex.ru[77.88.21.89]:25, delay=1.7, delays=0.01/0/1.1/0.57, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued on mxfront5.mail.yandex.net as nQ3GA6S5-nR3eE9tc)

подскажите, с чем может быть связана данная проблема?