After an upgrade de 3.1.2.4 to 3.3.0.8, I have noticed that when every author is making a submission, the submission acknowledgement email is not being sent to author,an appears the following message, for other things that send emails automatically work fine.
However the notification of new submision was sent to the journal gestor and editor, Why is the reason that the email is not being sent to the author?.
Reviewing my Apache error logs file this is the resulting message:
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Did you check the contact section of the journal?
Settings > Journal > Contact tab. There are some mandatory fields, including email.
Hi, @gonzalognzl I checked the contact tab and I resolved the problem but the load time for make the submission is stil too long, so Do you know a form to improve the performance of this function and the page in general? Thank you so much.
Glad the mail issue was solved 
For that, I guess you should have to open a new thread and put in some more details that could guide those willing to help you in that topic.