A client ends a nine-month agency engagement on good terms. They have the results, they have the lead list, and they are ready to bring it in-house.
Then they discover the twelve sending domains are registered to the agency. The mailboxes sit in the agency’s tenant. The DNS is administered in an account nobody at the client has ever logged into.
They are not being held hostage. Nobody did anything underhanded. It simply never came up, and now nine months of warmed sender reputation belongs to somebody else.
This happens constantly and it is entirely preventable with one question asked before signing.
What you actually lose
It is tempting to think domains are cheap, so starting again is a minor annoyance. Domains are cheap. What sits on top of them is not.
Sender reputation. Inbox providers score the domain, and that score is built from months of consistent sending behaviour. It does not transfer to a new domain. A fresh domain starts unknown, which is functionally worse than neutral.
The warmup investment. Three to four weeks per domain, and you cannot compress it. Twelve domains means a sequential or parallel ramp before you are back at working volume.
Time at full volume. Realistically six to ten weeks from standing start to the sending volume you had the day the contract ended. During which your pipeline is running at a fraction of normal.
Sometimes the conversations. If the mailboxes are in their tenant, the reply history is too. Every thread with a prospect who was mid-conversation when the engagement ended.
Put a number on it. If your outbound produces twenty meetings a month, losing two months of full volume costs you something like thirty meetings plus the rebuild effort. Against a domain portfolio worth perhaps $150 a year.
Why it happens
Rarely malice. Usually convenience.
Agencies set up infrastructure constantly, so they have registrar accounts, tooling and process ready. Doing it in their own account takes ten minutes; doing it in a client’s account means credentials, access, a call, and a client who does not understand DNS asking why they need twelve domains.
Retention is a secondary factor and worth naming. An agency whose infrastructure you depend on has a much stickier relationship than one whose labour you rent, and some agencies structure it that way deliberately. But most of the time it is simply the path of least resistance, which is exactly why asking early works so well.
The clauses to get in writing
Registration in your name. Domains registered to your company, on a registrar account you control, with the agency given delegated access. This is the whole fix. Everything else is cleanup.
DNS access. You hold the account; they get permission to edit records. If they hold the account, you cannot fix a broken SPF record without a support ticket to your former vendor.
Mailbox portability. Mailboxes should be exportable over SMTP and IMAP, so conversations and credentials come with you. If the mailboxes are inside a platform with no export path, the threads stay there.
A transfer clause. Explicit: on termination, all domains, DNS records and mailbox access transfer to the client within a stated number of days, at no cost. Put a number on the days.
Data export. The lead list with enrichment, the sequences, the performance data by segment. Not a PDF summary.
None of this is unreasonable and most agencies agree readily when asked before a contract starts. Asking during an exit conversation is a different negotiation with much worse leverage.
If you are already in this position
You have three routes, in order of preference.
Ask for a transfer. Most agencies will cooperate, particularly if you are leaving amicably. Domain transfers between registrars take five to seven days and need an auth code from the losing registrar. Start early. Do not stop sending during the transfer if you can avoid it, because a gap in sending does your reputation no favours.
Buy them. If they resist, offer to purchase the domains outright. It is a commercial conversation and the amount that makes the problem disappear is almost always less than the cost of rebuilding.
Rebuild in parallel. If neither works, start the new estate now rather than at the end. Register fresh domains, warm them alongside the existing ones, and migrate campaigns gradually as the new domains reach volume. It costs you a warmup cycle but not a pipeline gap, which is the expensive half.
One thing that does carry over regardless: your list, your offer and your messaging. The intangible asset is the knowledge of which segments respond and which openers work. Make sure that leaves with you even when the domains do not.
The same question applies to software
Domains are the sharpest version of this, but the principle generalises. Before committing to any part of your outbound stack, ask what leaves with you.
Can mailboxes be used with another sending tool, or are they locked to this platform? Can you export the lead list with enrichment intact, or only the names you uploaded? Does reply history export? Is there a data retention window after cancellation?
Portability is not a feature vendors advertise, because the incentive runs the other way. It is worth asking about anyway, and the answer tells you something about how the vendor thinks about the relationship.
The short version
Ask one question before you sign anything: whose registrar account will the domains sit in?
If the answer is the agency’s, ask for it to be yours with delegated access for them. That single change protects six to ten weeks of pipeline at the end of the relationship and costs nobody anything at the start.
And if you are already nine months in without having asked, ask now while things are going well. Exit conversations are a bad time to discover what you do not own.
Next: agency versus in-house, priced, or domain rotation and estate management.
Frequently asked questions
Who should own cold email domains, the client or the agency?
The client, registered to their company on an account they control, with the agency granted delegated access. The agency loses nothing operationally and the client keeps the warmed infrastructure when the engagement ends.
Can I transfer domains from an agency?
Yes. A standard registrar transfer needs an auth code from the current registrar and usually takes five to seven days. Most agencies cooperate. Start before you give notice, and keep sending during the transfer where possible.
Does sender reputation transfer to a new domain?
No. Domain reputation is built from that domain’s sending history and does not carry across. A new domain starts unknown and needs three to four weeks of warmup before it carries meaningful volume.
How long does it take to rebuild a cold email setup from scratch?
Six to ten weeks to return to previous sending volume, covering domain registration, authentication, warmup and ramp. The domains themselves cost very little; the time is the expense.
What else should be in an agency contract besides domains?
DNS account access, mailbox export over SMTP and IMAP, a transfer clause with a stated deadline, and export of the lead list with enrichment, sequences and segment-level performance data.