Here is a tcpdump of the behavior.
/Nick
21:36:39.495498 66.150.198.66.53222 > 213.190.4.14.smtp: S
1473373829:1473373829(0) win 5840 <mss 1460,sackOK,timestamp 89855336
0,nop,wscale 0> (DF)
0x0000 4500 003c f3ed 4000 4006 6429 4296 c642 E..<..@.@.d)B..B
0x0010 d5be 040e cfe6 0019 57d1 e685 0000 0000 ........W.......
0x0020 a002 16d0 2578 0000 0204 05b4 0402 080a ....%x..........
0x0030 055b 1568 0000 0000 0103 0300 .[.h........
21:36:39.605620 213.190.4.14.smtp > 66.150.198.66.53222: S
2071023715:2071023715(0) ack 1473373830 win 5792 <mss
1460,sackOK,timestamp 95093556 89855336,nop,wscale 0> (DF)
0x0000 4500 003c 0000 4000 2d06 6b17 d5be 040e E..<..@.-.k.....
0x0010 4296 c642 0019 cfe6 7b71 5063 57d1 e686 B..B....{qPcW...
0x0020 a012 16a0 50e3 0000 0204 05b4 0402 080a ....P...........
0x0030 05ab 0334 055b 1568 0103 0300 ...4.[.h....
21:36:39.605733 66.150.198.66.53222 > 213.190.4.14.smtp: . ack 1 win
5840 <nop,nop,timestamp 89855347 95093556> (DF)
0x0000 4500 0034 f3ee 4000 4006 6430 4296 c642 E..4..@.@.d0B..B
0x0010 d5be 040e cfe6 0019 57d1 e686 7b71 5064 ........W...{qPd
0x0020 8010 16d0 7f6d 0000 0101 080a 055b 1573 .....m.......[.s
0x0030 05ab 0334 ...4
21:36:39.974644 213.190.4.14.smtp > 66.150.198.66.53222: P 1:172(171)
ack 1 win 5792 <nop,nop,timestamp 95093593 89855347> (DF)
0x0000 4500 00df 535b 4000 2d06 1719 d5be 040e E...S[@.-.......
0x0010 4296 c642 0019 cfe6 7b71 5064 57d1 e686 B..B....{qPdW...
0x0020 8018 16a0 06ce 0000 0101 080a 05ab 0359 ...............Y
0x0030 055b 1573 3232 302d 656e 6465 722e 6833 .[.s220-ender.h3
0x0040 6d2e 636f 6d20 4553 4d54 5020 4578 696d m.com.ESMTP.Exim
0x0050 2033 2e33 3620 2331 204d 6f6e 2c20 3136 .3.36.#1.Mon,.16
0x0060 204a 756e 2032 3030 3320 3033 3a33 363a .Jun.2003.03:36:
0x0070 3339 202b 3032 3030 200d 0a32 3230 2d57 39.+0200...220-W
0x0080 6520 646f 206e 6f74 2061 7574 686f 7269 e.do.not.authori
0x0090 7a65 2074 6865 2075 7365 206f 6620 7468 ze.the.use.of.th
0x00a0 6973 2073 7973 7465 6d20 746f 2074 7261 is.system.to.tra
0x00b0 6e73 706f 7274 2075 6e73 6f6c 6963 6974 nsport.unsolicit
0x00c0 6564 2c20 0d0a 3232 3020 616e 642f 6f72 ed,...220.and/or
0x00d0 2062 756c 6b20 652d 6d61 696c 2e0d 0a .bulk.e-mail...
21:36:39.974757 66.150.198.66.53222 > 213.190.4.14.smtp: . ack 172 win
6432 <nop,nop,timestamp 89855384 95093593> (DF)
0x0000 4500 0034 f3ef 4000 4006 642f 4296 c642 E..4..@.@.d/B..B
0x0010 d5be 040e cfe6 0019 57d1 e686 7b71 510f ........W...{qQ.
0x0020 8010 1920 7c28 0000 0101 080a 055b 1598 ....|(.......[..
0x0030 05ab 0359 ...Y
21:36:39.975388 66.150.198.66.53222 > 213.190.4.14.smtp: P 1:7(6) ack
172 win 6432 <nop,nop,timestamp 89855384 95093593> (DF)
0x0000 4500 003a f3f0 4000 4006 6428 4296 c642 E..:..@.@.d(B..B
0x0010 d5be 040e cfe6 0019 57d1 e686 7b71 510f ........W...{qQ.
0x0020 8018 1920 d466 0000 0101 080a 055b 1598 .....f.......[..
0x0030 05ab 0359 5155 4954 0d0a ...YQUIT..
21:36:39.975578 66.150.198.66.53222 > 213.190.4.14.smtp: F 7:7(0) ack
172 win 6432 <nop,nop,timestamp 89855384 95093593> (DF)
0x0000 4500 0034 f3f1 4000 4006 642d 4296 c642 E..4..@.@.d-B..B
0x0010 d5be 040e cfe6 0019 57d1 e68c 7b71 510f ........W...{qQ.
0x0020 8011 1920 7c21 0000 0101 080a 055b 1598 ....|!.......[..
0x0030 05ab 0359 ...Y
21:36:40.085226 213.190.4.14.smtp > 66.150.198.66.53222: . ack 7 win
5792 <nop,nop,timestamp 95093604 89855384> (DF)
0x0000 4500 0034 535c 4000 2d06 17c3 d5be 040e E..4S\@.-.......
0x0010 4296 c642 0019 cfe6 7b71 510f 57d1 e68c B..B....{qQ.W...
0x0020 8010 16a0 7e97 0000 0101 080a 05ab 0364 ....~..........d
0x0030 055b 1598 .[..
21:36:40.085236 213.190.4.14.smtp > 66.150.198.66.53222: P 172:210(38)
ack 7 win 5792 <nop,nop,timestamp 95093604 89855384> (DF)
0x0000 4500 005a 535d 4000 2d06 179c d5be 040e E..ZS]@.-.......
0x0010 4296 c642 0019 cfe6 7b71 510f 57d1 e68c B..B....{qQ.W...
0x0020 8018 16a0 6d91 0000 0101 080a 05ab 0364 ....m..........d
0x0030 055b 1598 3232 3120 656e 6465 722e 6833 .[..221.ender.h3
0x0040 6d2e 636f 6d20 636c 6f73 696e 6720 636f m.com.closing.co
0x0050 6e6e 6563 7469 6f6e 0d0a nnection..
21:36:40.085389 66.150.198.66.53222 > 213.190.4.14.smtp: R
1473373836:1473373836(0) win 0 (DF)
0x0000 4500 0028 0000 4000 4006 582b 4296 c642 E..(..@.@.X+B..B
0x0010 d5be 040e cfe6 0019 57d1 e68c 0000 0000 ........W.......
0x0020 5004 0000 bedd 0000 P.......
21:36:40.086009 213.190.4.14.smtp > 66.150.198.66.53222: F 210:210(0)
ack 8 win 5792 <nop,nop,timestamp 95093604 89855384> (DF)
0x0000 4500 0034 535e 4000 2d06 17c1 d5be 040e E..4S^@.-.......
0x0010 4296 c642 0019 cfe6 7b71 5135 57d1 e68d B..B....{qQ5W...
0x0020 8011 16a0 7e6f 0000 0101 080a 05ab 0364 ....~o.........d
0x0030 055b 1598 .[..
21:36:40.086075 66.150.198.66.53222 > 213.190.4.14.smtp: R
1473373837:1473373837(0) win 0 (DF)
0x0000 4500 0028 0000 4000 4006 582b 4296 c642 E..(..@.@.X+B..B
0x0010 d5be 040e cfe6 0019 57d1 e68d 0000 0000 ........W.......
0x0020 5004 0000 bedc 0000 P.......
12 packets received by filter
0 packets dropped by kernel
--
J. Nick Koston <nick@???>
cPanel, Inc.