AsposeException: The server returned an invalid response to the TOP command

Hello,
what does this error mean?

AsposeException: The server returned an invalid response to the TOP command.StatusCode: NotDefined, Response:
—> AsposeException: The server returned an invalid response to the TOP command.StatusCode: NotDefined, Response:
—> AsposeException: The server returned an invalid response to the TOP command.StatusCode: NotDefined, Response:
—> Pop3Exception: The server returned an invalid response to the TOP command.StatusCode: NotDefined, Response:
at #=zGVRO8tomm4w$cbyn9$LVXIVmEKqktOYgLw==.#=zrtuLlHhUBIM7()
at #=zoWVjMrgrcQft2HAxRMLNUkBCVtrZZMBqsw==.#=zL5xEOEc=(Object #=zD09uWds=)
— End of inner exception stack trace —
at #=zpNUu6g91mUgI0L25lPgXA8SDP1SD.#=zXkkrGdQ=(IAsyncResult #=zRiTvjmQ=)
at #=zpNUu6g91mUgI0L25lPgXA8SDP1SD.#=zXkkrGdQ=()
at #=zoWVjMrgrcQft2HAxRMLNUkBCVtrZZMBqsw==.#=zqMBr6RU=(Object #=zD09uWds=)
— End of inner exception stack trace —
at #=zpNUu6g91mUgI0L25lPgXA8SDP1SD.#=zXkkrGdQ=(IAsyncResult #=zRiTvjmQ=)
at #=zpNUu6g91mUgI0L25lPgXA8SDP1SD.#=zHROmey8=()
at #=zFVrBcBbHxHuVScJj5zqxO_0IZlKlmFZbEVURj5A=.#=zNimUadM=()
at #=zO_9d6shDg5NnowV39cO6HR1$lfr_kKADAA==.#=zqqlmsvnE0FW3()
— End of inner exception stack trace —
at #=zpNUu6g91mUgI0L25lPgXA8SDP1SD.#=zXkkrGdQ=(IAsyncResult #=zRiTvjmQ=)
at #=zpNUu6g91mUgI0L25lPgXA8SDP1SD.#=zXkkrGdQ=()
at Aspose.Email.Clients.CredentialsByHostClient.#=zjmfmlZWfim8z(IAsyncResult #=zRiTvjmQ=)
at Aspose.Email.Clients.Pop3.Pop3Client.EndGetMessageInfo(IAsyncResult asyncResult)
at Aspose.Email.Clients.Pop3.Pop3Client.GetMessageInfo(Int32 sequenceNumber)
at MailCCPOP3.Mail.Main()

Thanks
Max

@cocci,
Thank you for the query. We cannot point out exactly the reason for the exception. Could you enable activity logging and share a log file with us, please?

Aspose.Email.Pop3_2021-6-22.zip (743.4 KB)

Here the log.

I get error when i try to get the message information:

Dim uid = asposePOP3.GetMessageInfo(i).UniqueId

Thanks
Max

@cocci,
Thank you for the additional information. I will answer you later.

Additional info:

the broken instruction is:

Dim temp = asposePOP3.GetMessageInfo(i)

Hello,
I just found that was a particular email that generated the error.
In the log i attached before, you can find it at row 57.
I deleted it from the server and the process has resumed to work.

@cocci,
Did I understand correctly that the issue has already been resolved on your side?

Yes, just deleting the email i mentioned.
My boss asked me why it happened and how to prevent a new fault…
Can you investigate, please?

Thanks
Max

@cocci,
To investigate this case on our side further, please share and specify the following:

  • comprehensive code example causing the exception
  • description of client/server environments
  • email file