Thank you for contacting eNom Technical support for email related questions. My name is Peter and I will be happy to help.
Our email supports 40MB inbound attachments and 20MB outbound attachments. The 20MB limit only applies to webmail and you can sent larger attachments on outbound emails when sending out via a mail client.
There is no hourly sending limit of outbound emails per mailbox.
However, all email users are expected to abide by the email terms of use. If a mailbox gets flagged for spam then that mailbox would be prohibited from sending email.
If you are sending out lots of emails such as a mailing list, please be certain that the recipients are requesting those emails and have a way to opt out from receiving those emails if they desire.
I will be happy to assist if you have any additional questions about this matter so please feel free to update this ticket at any time.