You gave me an idea.
I reproduced the exact error message and resent it using "logger" bash utility.
No alarms fired.
So I tried it in another host and this time it works!
It is incredible.
I have tcpdump, this one from host called "pvehpbig" works:
05:42:12.998464 IP 10.1.0.4.46393 > mon-netxms.syslog: SYSLOG user.notice, length: 48
0x0000: 4500 004c 67fa 4000 4011 be5d 0a01 0004 E..Lg.@.@..]....
0x0010: 0a01 0044 b539 0202 0038 064b 3c31 333e ...D.9...8.K<13>
0x0020: 4a61 6e20 2034 2030 363a 3434 3a31 3420 Jan..4.06:44:14.
0x0030: 7076 6568 7062 6967 2065 7665 3470 7665 pvehpbig.eve4pve
0x0040: 2d62 6172 633a 2070 726f 7661 -barc:.prova
This one from host called siippve1 does not work:
05:43:30.834995 IP 10.2.1.240.50964 > mon-netxms.syslog: SYSLOG user.notice, length: 48
0x0000: 4500 004c 2b24 4000 3c11 fd46 0a02 01f0 E..L+$@.<..F....
0x0010: 0a01 0044 c714 0202 0038 f1a6 3c31 333e ...D.....8..<13>
0x0020: 4a61 6e20 2034 2030 363a 3435 3a33 3220 Jan..4.06:45:32.
0x0030: 7369 6970 7076 6531 2065 7665 3470 7665 siippve1.eve4pve
0x0040: 2d62 6172 633a 2070 726f 7661 -barc:.prova
It seems the same message to me!
Mario