OpenGPG Signing doesn't work.

Based on the output, it seems like it's hanging. You can try enabling debug output like this (in the Terminal):

defaults write com.freron.MailMate MmDebugSecurity -bool YES

And then launch MailMate like this:

/Applications/MailMate.app/Contents/MacOS/MailMate

Part of the output is the gpg2 command used and its arguments. You can try that manually and see if that works.

Thanks in advance.

input: 'Content-Type: text/plain

testsetsetset'
OpenPGP
gpg2 --no-verbose --batch --no-tty --openpgp --status-fd 2 --digest-algo SHA1 --textmode --armor --detach-sign --local-user "[neutered]" Input string (45): "Content-Type: text/plain\r\n\r\ntestsetsetset" Result: Failure Output string (0): "" Detail: [GNUPG:] USERID_HINT [neutered] Detail: [GNUPG:] NEED_PASSPHRASE [neutered] [neutered] 17 0 Detail: [GNUPG:] GOOD_PASSPHRASE Detail: [GNUPG:] BEGIN_SIGNING H2 Detail: gpg: DSA key [neutered] requires a 256 bit or larger hash Detail: gpg: signing failed: General error 2014-04-29 15:11:32.953 MailMate[57649:507] Warning: Unknown security problem (OpenPGP): unknown
2014-04-29 15:11:32.954 MailMate[57649:507] Warning: Unknown security problem (OpenPGP): unknown
2014-04-29 15:11:32.981 MailMate[57649:507] Warning: Unknown security problem (OpenPGP): unknown

Apparently, it's the strength of my key that doesn't work with the command line option of "--digest-algo SHA1" Changing it from "--digest-algo SHA1" to "--digest-algo SHA256" works.

I am encountering the same error and have taken the steps suggested above.

MM's signing dialog looks like:

USERID_HINT NEED_PASSPHRASE 2515EAB55D06505D 2515EAB55D06505D 17 0 GOOD_PASSPHRASE BEGIN_SIGNING H2

The console lists this:

2015-01-20 10:54:49.591 MailMate[63122:10568022] Warning: Unknown security problem (OpenPGP): unknown

Not particularly detailed.

I am using MM build 5035 and the newest GPG Suite (Beta 4 for Yosemite).
Thanks,
John

I was having this problem as well and it SEEMED like the preference change didn't take, because even after the change when I tried again to re-send the failed test message from the Drafts folder, the debug output showed:

OpenPGP
gpg2 --no-verbose --batch --no-tty --openpgp --status-fd 2 --digest-algo SHA1 --textmode --armor --detach-sign --local-user "bill@scconsult.com"

This appears to be because MM is saving drafts which were set to be signed when they were saved with this header:

Content-Type: multipart/signed;
boundary="=_MailMate_432EC9DA-1963-489E-BD0A-1D3F06BFD353_="; micalg=pgp-sha1; protocol="application/pgp-signature"

The workaround for this is to open the draft that couldn't be signed before the setting change, unset the signature toggle, save it, then re-open it and turn signing back on.