My mta is logging a connection, which times out every three minutes. The strace for the out runner shows the following:

fstat(20, {st_mode=S_IFREG|0660, st_size=3063808, ...}) = 0 stat("/var/lib/mailman3/data/mailman.db", {st_mode=S_IFREG|0660, st_size=3063808, ...}) = 0 pread64(20, "SQLite format 3\0\20\0\1\1\0@ \0\0\1\32\0\0\2\354"..., 100, 0) = 100 fcntl(20, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=1073741824, l_len=1}) = 0 fcntl(20, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=1073741826, l_len=510}) = 0 fcntl(20, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=1073741824, l_len=1}) = 0 stat("/var/lib/mailman3/data/mailman.db-journal", 0x7fff3e9a8120) = -1 ENOENT (No such file or directory) stat("/var/lib/mailman3/data/mailman.db-wal", 0x7fff3e9a8120) = -1 ENOENT (No such file or directory) fstat(20, {st_mode=S_IFREG|0660, st_size=3063808, ...}) = 0 pread64(20, "SQLite format 3\0\20\0\1\1\0@ \0\0\1\32\0\0\2\354"..., 4096, 0) = 4096 pread64(20, "\r\0\0\0\26\2\7\0\17\212\17E\16\372\16\230\16Y\f\220\n\240\n-\t\273\tI\10\300\10o"..., 4096, 106496) = 4096 pread64(20, "\0\0\0\0changes BOOLEAN, \n\tadministr"..., 4096, 32768) = 4096 pread64(20, "\r\v\234\0\23\0\333\0\r0\n\253\n5\t\240\10\201\7\370\6\324\6e\5\340\5\4\4\206\4\24"..., 4096, 114688) = 4096 pread64(20, "\r\0\330\0\24\0\231\0\v\266\vE\n\351\t\352\t\261\10f\7\305\0073\5,\4\305\4n\3\370"..., 4096, 208896) = 4096 fcntl(20, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0 fcntl(20, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=1073741824, l_len=1}) = 0 fcntl(20, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=1073741826, l_len=510}) = 0 fcntl(20, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=1073741824, l_len=1}) = 0 stat("/var/lib/mailman3/data/mailman.db-journal", 0x7fff3e9a92f0) = -1 ENOENT (No such file or directory) pread64(20, "\0\0\1\32\0\0\2\354\0\0\0\0\0\0\0\0", 16, 24) = 16 stat("/var/lib/mailman3/data/mailman.db-wal", 0x7fff3e9a92f0) = -1 ENOENT (No such file or directory) fstat(20, {st_mode=S_IFREG|0660, st_size=3063808, ...}) = 0 pread64(20, "\n\0\0\0\20\16\270\0\17\325\17N\17\304\179\17\262\17%\17\237\17\357\17\207\17\17\17w\16\371"..., 4096, 36864) = 4096 pread64(20, "\5\0\0\0\3\17\361\0\0\0\2\301\17\373\17\366\17\361\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096, 28672) = 4096 pread64(20, "\r\0\0\0\4\0020\0\0020\f\274\10a\5H\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096, 270336) = 4096 fcntl(20, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0 fcntl(20, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=1073741824, l_len=1}) = 0 fcntl(20, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=1073741826, l_len=510}) = 0 fcntl(20, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=1073741824, l_len=1}) = 0 stat("/var/lib/mailman3/data/mailman.db-journal", 0x7fff3e9a9390) = -1 ENOENT (No such file or directory) pread64(20, "\0\0\1\32\0\0\2\354\0\0\0\0\0\0\0\0", 16, 24) = 16 stat("/var/lib/mailman3/data/mailman.db-wal", 0x7fff3e9a9390) = -1 ENOENT (No such file or directory) fstat(20, {st_mode=S_IFREG|0660, st_size=3063808, ...}) = 0 pread64(20, "\2\r \0\31\fL\24\0\0\2\25\f\306\rO\17?\r\354\16-\ro\r\302\r\6\16d\r\211"..., 4096, 192512) = 4096 pread64(20, "\n\2\241\0\177\1k\1\17<\16\236\1\360\2\206\16\203\16h\16J\16.\1k\16\17\r\360\r\327"..., 4096, 1032192) = 4096 fcntl(20, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0 clock_gettime(CLOCK_REALTIME, {tv_sec=1634752684, tv_nsec=599142985}) = 0 clock_gettime(CLOCK_REALTIME, {tv_sec=1634752684, tv_nsec=599473757}) = 0 getpid() = 1262375 write(17, "Oct 20 19:58:04 2021 (1262375) U"..., 101) = 101 clock_gettime(CLOCK_REALTIME, {tv_sec=1634752684, tv_nsec=600257524}) = 0 clock_gettime(CLOCK_REALTIME, {tv_sec=1634752684, tv_nsec=601667144}) = 0 getpid() = 1262375 write(17, "Oct 20 19:58:04 2021 (1262375) C"..., 59) = 59 socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_TCP) = 21 connect(21, {sa_family=AF_INET, sin_port=htons(465), sin_addr=inet_addr("127.0.0.1")}, 16) = 0 recvfrom(21,

And the mailman smtp-log shows:

Oct 20 19:58:04 2021 (1262375) <163474270655.1243104.7078333516263200191@xxx> delivery to xxx@xxx failed with code 444, Connection unexpectedly closed Oct 20 19:58:04 2021 (1262375) Using agent: <mailman.mta.bulk.BulkDelivery object at 0x7f219bf93310> Oct 20 19:58:04 2021 (1262375) Connecting to 127.0.0.1:465

when it times out.

The debug log also shows this:

Oct 20 18:42:46 2021 (1262296) [OutgoingRunner] doing periodic Oct 20 18:42:46 2021 (1262296) [OutgoingRunner] committing transaction Oct 20 18:42:46 2021 (1262296) [OutgoingRunner] checking short circuit Oct 20 18:42:46 2021 (1262296) [OutgoingRunner] short circuiting Oct 20 18:42:46 2021 (1262296) [OutgoingRunner] ending oneloop: 29

I have no clue as to what is going on. Has anyone experienced this before?