Email tips: Plus and Minus Addressing, Mimecast Sieve Sub Address policy

Written By Select Cybersecurity

+ and -- addressing is a handy trick to use when giving email addresses out to 3rd parties. When emails are received they will be delivered to the intended recipient but will contain the sub address as a way to track and organize where emails are coming from and how the sender obtained your email address.

For example support@selectcybersecurity.com can be written as support+emailwebinar@selectcybersecurity.com instead when signing up for an email webinar. When the invite comes to our support inbox we will have information about how this invite found us because it will show the sub address in the “to” information. -- addressing works the same way except you append the sub address to the front such as emailwebinar--support@selectcybersecurity.com.

NOTE: Mimecast by default does not allow + or --addressing to be delivered to your environment. If you’d like to utilize it you have some options for enabling it under the Sieve Sub Address policy.

NOTE: Office 365 by default does not allow -- addressing but does allow + addressing.

NOTE: Mimecast will require 2 policies if you want to use both types of sub-addressing but the scope of the policies need to be considered because of the prioritization of policies - only 1 policy can apply to inbound mail for this.

 

You can see within the policy that your options are as follows:

 

“Select the appropriate option:

  • Enable + delimiter recognition - (e.g. user+sieve@domain.com. The Mimecast Gateway will ignore the Sieve Sub extension for the Inbound Check and policy processing but will deliver the item to the address that includes the Sieve Sub extension)

  • Enable -- delimiter recognition - (e.g. user--sieve@domain.com. The Mimecast Gateway will ignore the Sieve Sub extension for the Inbound Check and policy processing but will deliver the item to the address that includes the Sieve Sub extension)

  • Enable + delimiter recognition and removal - (e.g. user+sieve@domain.com. The Mimecast Gateway will remove the Sieve Sub extension for the Inbound Check and policy processing and will deliver the item to the address minus the Sieve Sub extension)”

If you have difficulties just let us know and we can assist.

Select Cybersecurity
Next

DKIM 2048 in Mimecast