Removing and Re-adding Domain and MX Records

I recently removed a domain from domain manager, and then re-added so I could point it to a different directory. When doing so, a message showed saying something like "No files will be lost if you proceed." However, after doing, domain emails could no longer be sent that were running through gmail. The "no files will be lost..." message made me think it was safe to remove/re-add the domain, though did doing so reset the MX records? Because, afterwards they were no longer pointed to Google and some emails were lost. Thank you for any feedback.