Purchased a new version of Express Invoice, installed on new PC, configured SMTP exactly as the old PC, but when sending an invoice I get the error "mail server not responding (421)".
Summary: Old PC with previous version of Express Invoice sends invoices, new PC with new version does not, settings are configured the same.
SMTP server: mail.myserver.com:1025
Authentication Username: info@myserver.com Password: password
SMTP server requires a secure connection: No
Any help will be much appreciated.