Mass email sending problem

Hi everyone.
I was looking for a solution about the same (I suppose) problem but I do not see any more notifications from the author, so I would write here instead of start a new topic.
Please let me know if I should do differently.
I use OJS 2.4.8.0 version.
As Editor, I click on “Notify Issue” and select the first option “Send this message to all users associated with this journal” (1337 users in that case).
After a while, I receive the following advice:
"“Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator to inform of the time the error occurred and of anything you might have done that may have caused the error.
More information about this error may be available in the server error log.”

I searched into the error log and found out these texts maybe helpful in understanding; consider that 3th April was the day of the notification, so I report here only that part of the log:


[Mon Apr 03 11:16:59 2017] [warn] [client 151.100.51.130] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server, referer: http://periodicodimineralogia.it/index.php/mineralogia/editor/notifyUsers
[Mon Apr 03 11:16:59 2017] [warn] [client 151.100.51.130] (104)Connection reset by peer: mod_fcgid: ap_pass_brigade failed in handle_request_ipc function, referer: http://periodicodimineralogia.it/index.php/mineralogia/editor/notifyUsers
[Mon Apr 03 11:32:43 2017] [warn] [client 151.100.51.130] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server, referer: http://periodicodimineralogia.it/index.php/mineralogia/editor/notifyUsers
[Mon Apr 03 11:32:43 2017] [warn] [client 151.100.51.130] (104)Connection reset by peer: mod_fcgid: ap_pass_brigade failed in handle_request_ipc function, referer: http://periodicodimineralogia.it/index.php/mineralogia/editor/notifyUsers
[Mon Apr 03 11:41:22 2017] [warn] [client 151.100.51.130] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server, referer: http://periodicodimineralogia.it/index.php/mineralogia/editor/notifyUsers
[Mon Apr 03 11:41:22 2017] [warn] [client 151.100.51.130] (104)Connection reset by peer: mod_fcgid: ap_pass_brigade failed in handle_request_ipc function, referer: http://periodicodimineralogia.it/index.php/mineralogia/editor/notifyUsers


It seems to me some kind of problem with the FastCGI server but I do not know what it is =(
Does anyone know anything about it?
Thanks a lot =)

Chiara - Nuova Cultura