CITMTA & CIT FixCIT Tools

MTA:SA error code

MTA:SA error CD02

There is no active connection for MTA to work with.

Code
CD02
Where you see it
The connection dialog
MTA's own wording
No active connection
Family
CD codes

What it means

A CD code appears when a connection to a server fails, is refused, or ends. Most of them carry a second line with the server's own reason. MTA's own documentation gives this code as No active connection.

How to fix it

Work down the list and stop when it is solved.

  1. Try the connection again

    Close MTA, open it again and connect once more. A single failed attempt can come from a restart on the server or a short break in your own connection.

  2. Copy the whole message first

    Write down every line MTA shows, not only the code. The rest of the message often names the file, the server or the reason, and that is what tells you which step below applies.

Still stuck? The Fix tool reads MTA's own log on your computer and points at the matching steps. Nothing is uploaded.

Open the Fix tool

Other CD codes

Where this comes from

Official Error Codes catalog; full message and issuer remain necessary.

Meanings read from these sources on 5 September 2026 and written in our own words here.