Could not instantiate mail function

This is definitely the most common error message you will get if you have trouble sending e-mails using your server and unfortunately, this error message does not tell you how you can solve the issue.

Technically, the phpMailer library (a famous php library to send e-mails... used by AcyMailing and Joomla) tried to send a message using the php mail() function and the php mail() function returned "false".

Based on our experience it can be:

• You are on a local server
• Your receiver e-mail address is not valid
• You included a special character in the subject
• You included a special character in the sender/receiver information
• The bounce address you specified is not accepted by your server
• You already sent too many e-mails

You are on a local server (using WAMP for example)

This kind of web server does not have a mail server so you can't send e-mails from your local server.

What's the solution? Well, you should configure AcyMailing to use an external SMTP server instead of using the php Mail function to test Acy but you can consider it will work on your live server

Your receiver e-mail address is not valid

Your mail server may refuse to deliver your message if the receiver e-mail address is not a valid one... So if you have this "could not instantiate mail function" for only a few of your subscribers, it may just be because their e-mail address is not valid!

You included a special character in the subject line

Some mail servers will refuse to deliver your message if it contains special characters in the subject such as a quote or a comma or any other kind of special character (ùïä)...

Please create a new Newsletter, specify a standard subject line ("test" for example) and give it a new try.

You included a special character in the sender/receiver information

The same way, some mail server will refuse to deliver your message if the sender information contain special characters.

Please go on the AcyMailing configuration page, turn OFF the option "add Names" and give it a new try.

The bounce address you specified is not accepted by your server

Some servers won't accept to deliver your message if you specify a bounce e-mail address.
Others will force you to apply a bounce address which belongs to your own domain...

Please go on the AcyMailing configuration page and leave the bounce address field empty.

You already sent too many e-mails!

Most of hosting company will allow you send X e-mails per hour.
If you go over that limitation, the mail server will refuse to deliver more e-mails and will display this error message.
So for example if you successfully sent 480 e-mails and you can't send e-mails any more, then it's probably what happened and you should first wait one hour to deliver more e-mails and also make sure AcyMailing is configured to stay below your sending limitations.