Hello, My name is David. Email programs typically unblock all addresses that are listed in your Contacts. So add the 123Greetings.com email address from one of the email cards you previously received into your contact settings and then test to confirm that the issue is resolved.
Most likely however this is something you have no control over it is a war between 123greetings and yahoo with some spam stopping company in between. They have probably been identified as sending spam by a third party service that yahoo uses to set up its own block list.
After that, please go to Menu > My Bookings > Manage Flights. Then provide the information needed. Lastly, please select the Booking that you have an issue with. Then select the Edit button and correct your birthday.