I have a data extension with a 'subjectline' column with the content '%%FirstName%%, check out this great subject line'. I then have a code snippet content block that has a set of if statements which determine what row/subject line the recipient should get. I then place %%=ContentBlockbyId("147137")=%% in the subject line section referencing the code snippet content block.
The content picks up fine, however the %%FirstName%% tag just appears as plain text. Is it possible to get this to pull in the recipients first name from the sending DE? Or will it always be read as plain text?