mendelson AS2 solution – “[SSLPeerUnverifiedException]: peer not authenticated … Connection problem, failed to transmit data.”

When you send a file to your partner the trasmission fails with the following error message:

[SSLPeerUnverifiedException]: peer not authenticated
Connection problem, failed to transmit data.

If the software is configured properly and you have managed to send files then the problem is software related.

Solution 1:

Download and install the latest version

My experience: with (AS2 1.1 b33) I could send a maximum of 5 consecutive files, I received the error over the fifth file and had to wait 10 minutes until half an hour before I can resubmit the files.

Solution 2:

Update all Expired Certificates in
and in

I suggest you use
Portecle, a user friendly GUI application for creating, managing and examining keystores, keys, certificates, certificate requests, certificate revocation lists and more.
Portecle can be launched directly with Java Web Start (Java 1.6 or later with Web Start required) from
or downloaded from
extract the folder, start Command Prompt Window (Start -> Run -> cmd) and execute the following command:

C:\portecle-1.7>java -jar portecle.jar

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