Linux

 openssl s_client -connect 202.128.246.114:25 -starttls smtp -debug
CONNECTED(00000004)
read from 0xa0018da00 [0xa00078cf0] (4096 bytes => 0)
write to 0xa0018da00 [0xa00079d00] (23 bytes => 23 (0x17))
0000 - 45 48 4c 4f 20 6d 61 69-6c 2e 65 78 61 6d 70 6c   EHLO mail.exampl
0010 - 65 2e 63 6f 6d 0d 0a                              e.com..
read from 0xa0018da00 [0xa00078cf0] (4096 bytes => 0)
Didn't find STARTTLS in server response, trying anyway...
write to 0xa0018da00 [0x7ffffbd00] (10 bytes => 10 (0xA))
0000 - 53 54 41 52 54 54 4c 53-0d 0a                     STARTTLS..
read from 0xa0018da00 [0xa00016ec0] (8192 bytes => 0)
write to 0xa0018da00 [0xa001acd60] (313 bytes => 313 (0x139))
0000 - 16 03 01 01 34 01 00 01-30 03 03 7b f2 2d 05 7b   ....4...0..{.-.{
0010 - c3 e6 36 1c 6a a0 e2 62-56 8a 8d 2c 8c d7 ac cc   ..6.j..bV..,....
0020 - d1 48 5d 27 0b 5e e5 6e-94 21 76 20 c9 4f fd 97   .H]'.^.n.!v .O..
0030 - 0c e1 47 3b e6 be 05 3a-ae c8 11 51 ef 79 ce 7d   ..G;...:...Q.y.}
0040 - 33 df 85 3a 35 ab 16 df-c6 f1 11 d9 00 48 13 02   3..:5........H..
0050 - 13 03 13 01 13 04 c0 2c-c0 30 cc a9 cc a8 c0 ad   .......,.0......
0060 - c0 2b c0 2f c0 ac c0 23-c0 27 c0 0a c0 14 c0 09   .+./...#.'......
0070 - c0 13 00 9d c0 9d 00 9c-c0 9c 00 3d 00 3c 00 35   ...........=.<.5
0080 - 00 2f 00 9f cc aa c0 9f-00 9e c0 9e 00 6b 00 67   ./...........k.g
0090 - 00 39 00 33 00 ff 01 00-00 9f 00 0b 00 04 03 00   .9.3............
00a0 - 01 02 00 0a 00 16 00 14-00 1d 00 17 00 1e 00 19   ................
00b0 - 00 18 01 00 01 01 01 02-01 03 01 04 00 23 00 00   .............#..
00c0 - 00 16 00 00 00 17 00 00-00 0d 00 30 00 2e 04 03   ...........0....
00d0 - 05 03 06 03 08 07 08 08-08 09 08 0a 08 0b 08 04   ................
00e0 - 08 05 08 06 04 01 05 01-06 01 03 03 02 03 03 01   ................
00f0 - 02 01 03 02 02 02 04 02-05 02 06 02 00 2b 00 09   .............+..
0100 - 08 03 04 03 03 03 02 03-01 00 2d 00 02 01 01 00   ..........-.....
0110 - 33 00 26 00 24 00 1d 00-20 eb ba c3 77 1a 96 0a   3.&.$... ...w...
0120 - 20 c0 c1 77 36 bd 21 67-53 7d 0b 39 e5 2a 0f c6    ..w6.!gS}.9.*..
0130 - 17 8b 55 8a 9b df 5f 11-02                        ..U..._..
read from 0xa0018da00 [0xa0007e263] (5 bytes => 0)
write to 0xa0018da00 [0xa001acd60] (7 bytes => 7 (0x7))
0000 - 15 03 01 00 02 02 32                              ......2
100000000A000000:error:0A000126:SSL routines:ssl3_read_n:unexpected eof while reading:ssl/record/rec_layer_s3.c:322:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 353 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---
read from 0xa0018da00 [0xa00016ec0] (8192 bytes => 0)