A maximum number of recipients per each generated notification email message can be configured. This ensures that in the case of a long list of recipients, recipients are broken up and multiple emails are generated in order to prevent timeout errors. To configure a maximum number of recipients per email:
In the Configuration module, navigate to Utils | Distribution Service Settings. The Distribution Service Settings dialog box is displayed:
In the Maximum recipients per mail message field, enter the maximum number of recipients that a message should have. If the recipient list is longer than the value of this setting, emails are sent in multiple batches.
If you do not want a maximum number of recipients per mail message, set the Maximum recipients per mail message value to 0. This does not set a maximum number of recipients. A single message is generated for all recipients.