After a recent upgrade to openssl-1.1.0c I can't connect to the IMAP-Server at work anymore. Connecting to other IMAP-Servers (e.g. imap.gmx.de:993) works without problems, using the exact same command.
When trying to connect to the server using
openssl s_client -connect mbox.uni-stuttgart.de:993
I am getting the following error:
CONNECTED(00000003) 140093138867328:error:14094417:SSL routines:ssl3_read_bytes:sslv3 alert illegal parameter:ssl/record/rec_layer_s3.c:1388:SSL alert number 47
The server is running the CommuniGate Pro Suite.
Here's what I have tested so far:
- Connecting from another machine with OpenSSL 1.0.1t works flawless.
- Connecting to other secure services on the same target machine that offer SSLv3 (not e-mail related: Apache server) works flawless.
Any clues about why the connection to the e-mail related services lead to the error mentioned above would be highly appreciated!