Remittance Advice Emails not being generated to Outlook



I use to have no problem generating remittance advice to my Outlook draft folder when running the Generate Payments feature. Now though I am getting this -

The above pop up box appears as many times as there are suppliers on the list (we do batch payments). Once I have clicked through this error then the below message box pops up listing all the remittance advice that was not generated (all the suppliers in the batch)

Finally the below box appears

After which the process has finished but no remittance advise is my draft folder in Outlook which use to happen.

Please can someone help?

Many thanks