User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

Since the latest updates (60.5.2) I can not send an Email about another program. For example: Windows -> Send to -> Mail rcipient. Appears the warning, i can confirme the operation, but the email does not open.

UPDATE!!!! The emails sents immidiatly!! I can not change the email befor sending!!

Check "Fixed in new version": Crash when using "Send to > Mail recipient" on Windows under some circumstances (MAPI interface)

When I get the parameter mai.blind-sent.enabled to false, apparse the message "Couldn't send email: General MAPI failire[2]"

Summery:

• If I send an Email without receiver-address (Send to > Mail recipient on Windows), the email will not be send. No windows for "new email" appears.
• If I send an Email with receiver-address (send email from erp, order to supplier), the email will be send immediatly. No windows appears to modify the email before sending.

Dup of Bug 1530820 is what I am thinking.

Interesting observation, BTW, the pref is called mapi.blind-send.enabled.

The logic is this:
The application calling Thunderbird to send e-mail via the MAPI interface can set the MAPI_DIALOG flag. If this is not set, TB will send e-mail without dialogue, see:
https://searchfox.org/comm-central/rev/10f11d2e56748e92fa3365cbe1e68a55a20d2a67/mailnews/mapi/mapihook/src/msgMapiImp.cpp#223

This function can be seen here:
https://searchfox.org/comm-central/rev/10f11d2e56748e92fa3365cbe1e68a55a20d2a67/mailnews/mapi/mapihook/src/msgMapiHook.cpp#293

If blind sending is not allowed by setting the preference to false, an error is returned.

So I can see this works as designed. The external application should set the MAPI_DIALOG flag if a dialogue is desired.

That sending with dialogue doesn't work now is filed in bug 1530820. We still don't quite understand why that happens. I have two machines where that works and one where it doesn't. The latter has Outlook installed. Do you have Outlook installed?

All that said, none of the code surrounding the dialogue flag has changed. It still looks like for some reason the MAPI DLL called by Windows and the counterpart in Thunderbird are mismatched, since the interface between the two changed. That's why the dialogue flag may get lost.

If I take MsOutlook as standard-application works. I tried with

• Send to Email (from Windows 7/10)
• Send Email with out ERP-System; opens an Email with attachement and rec.address.

Does bug 1530820 comment #30 help?

Yes, thank you! Exception: https://bugzilla.mozilla.org/show_bug.cgi?id=1530820#c91