I had a long password with many special characters. One of those characters was the double-quote character ", and mailwatch (as packaged in Debian Jessie) was unable to authenticate to the server. Next, I tried rolling my own package using the latest git master HEAD (commit d046d61ea277ad5432dc33130d6efd6d6dd8f317), re-added and reconfigured the applet and tried again. Still no luck authenticating. Lastly, I removed the " character from my password (leaving all other characters including special characters in place), and finally mailwatch started working.
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