As you might know, Terra Mail will shut down their free email service at the end of June, specifically by the end of the day on June 30th. Since those domains will no longer be mailable, we will block any and all mail to the following domains on that date:
Of course even if we didn't set up new blocks to those domains you would not be able to reach those leads, but starting on June 30th those leads will bounce internally rather than from external sources.
Since Terra Mail was a popular email service in Spain and Latin America your marketing might not actually be affected by the closure if you do not do business in those regions. However, if you do, we recommend identifing engaged customers who have addresses at one of the above domains and ask them where they want to receiving their future communication.