Where your email actually lives
Your domain is an address book entry, not a building. The mailboxes themselves sit with a mail host, and your domain’s DNS records simply point deliveries there. That is the whole trick to understanding every domain and email question: the domain points, the mail host stores. Move the pointer carefully and the storage never notices.
Domain transfer email: what a transfer moves
A domain transfer moves the registration, the paperwork saying which registrar manages your name and whose details are on it, from one company to another. Done properly, the DNS records travel unchanged, and email flows exactly as before. The transfer itself takes a few days of the two registrars talking to each other, and your mail is being delivered normally the whole time. What a transfer does not do is touch a single message, folder or contact, because none of those live in the domain.
The one way mail genuinely breaks
Mail breaks when the DNS records change, not when the domain moves. The classic accident: the new registrar helpfully applies fresh default DNS, the old MX records vanish, and mail starts bouncing until someone notices. The same accident happens without any transfer at all, when a host resets DNS during some unrelated change. The fear is aimed at the wrong step, and knowing that is most of the protection.
The checklist that prevents it
Before any transfer: copy the full DNS zone, especially the MX and SPF records, and keep the copy somewhere that is not the old account. Unlock the domain and get the transfer code. After the move, confirm the records match the copy before touching anything else. Then send yourself a test message from an outside address. Our web hosting team runs this exact sequence on every migration we do, and it is also written into our free migration promise: mail keeps working, or we are not finished.
A bonus most people never hear
Transferring most domain extensions adds a year to the registration, because the transfer fee typically includes a renewal. You keep every remaining day you already paid for, and the new year stacks on top. It is one of the few pieces of domain plumbing that quietly works in your favour, and it pairs well with holding your name long-term, which we covered in the honest answer on owning a domain permanently.
The honest bit
If your domain, your email and your website all live tangled in an account someone else controls, the transfer is not the risky part, the tangle is. Untangle it once: domain registered in your name, DNS documented, mail host known. After that, transfers are paperwork. If the person currently holding your domain discourages the untangling, that tells you why it needs doing.