the server was fetching mail fine but we had hit a quota on the email server - we have since purged archive email and only using

12% of our quota.

however now no new mail is being received.

I tried to run it manually on the client but get the following error -

On the server the script doesn't fail and no errors are generated just no new mail is fetched.

It sounds like your server is using a self-signed certificate instead of a regular SSL certificate. I would recommend installing a regular certificate on your server again. You can read about this at http://dreamingthings.blogspot.com/2006/12/no-more-unable-to-find-valid.html if you are unable to install a regular certificate, but using a self-signed certificate is pretty insecure, so I do not recommend it. You have to allow the self-signed certificate on each client machine connecting to the server, so it's a lot of work to do that. Getting a real certificate is a much, much better solution.

Also, your server is going to be running into the same errors that you client is, but you probably aren't recording it anywhere. Our functions will return ERROR if there is an error, and you will need to either check your server logs or record the error in your database if you want to see it when running a scheduled script. FileMaker server won't show you that an error has occurred in the Admin Console when you look at the status of your script.

But this setup was working fine for the past 4 months and only when we hit the quota and then cleared the old email

are we being presented with this error?