A deferred email address means that the recipient's mail server has temporarily refused delivery of a message. If this occurs, we will attempt to send messages for up to 72 hours until the message is delivered. Normally, it takes between a few minutes to a few hours until the message is delivered.

What can cause an email to be deferred?

• The receiving server doesn’t recognize the community's email address and is afraid you’re sending spam. 
• The receiving email server doesn’t have any open ports to receive an email.
• The recipient’s mailbox is full.
• Some recipients have marked your mail as spam, and have blocked the community's email address or domain

What happens if it’s continuously deferred for 72 hours? 

Well, that generally means it’s an issue like the account being inactive, having a full mailbox, or some other legitimate problem with the recipient. When we are unable to deliver a message after this time period, we convert these deferrals to “Hard Bounces”. What this means is that even if you send a message through us to that user, we will not even try to deliver it to that address, because we know it’s no longer good. Continuing to try to send to a known bad address will harm your reputation with the receiver, so we prevent that. 

What can you do to check what caused a deferred email address?

1. Check with the member if they have marked your group email address as spam and if they have, make sure the member moves the group email address back to their white list or contact list
2. Check with the member you're trying to send a message to what their current email address is and if they are having issues receiving any other emails
3. Check with the member if their organization or IT needs to whitelist emails from mobilize.io in order to get past a firewall
4. Check if the email address you're trying to send to is a valid email address