New email restrictions have been put in place to protect the integrity and performance of our hosted email system. These include measures to block spoofed / unauthenticated emails, and revised sending & receiving limits.

Spoofed Email Prevention

To limit the ability of bad actors from using our service to send spoofing emails, we will begin enforcing additional verification on all emails sent from our system, to limit the available sending domains to ones on the same account as the authenticated user.

This change will not affect most users, if you send email from the same domain that you login as, you are fine. The only case where this would apply is if you had setup your email client to login with but told it to set the From field to

To accommodate the need to use sending-only domains or sub-domains, a domain alias can be added to an existing primary domain, on your account. Please contact us if you think you need this.

Sending & Receiving Limits

New sending limit: 10,000 recipients / day – Counting recipients is different than counting messages. For example, sending 100 emails that each have 100 recipients is counted the same as sending 10,000 emails that each have a single recipient.

New receiving limit: 400 messages / 10 minutes – If a mailbox receives over 400 messages in a 10-minute period, any additional messages in that period will be deferred. Email senders will typically retry a deferred message at least once, possibly resulting in the message still being delivered after a short delay.