Should you use a dedicated domain for prospecting? How to choose, configure and redirect your sending domains

It is often the first real technical question for a team getting started with email prospecting: should we send from our usual address, or should we buy another domain? Both options have merit. But they do not carry the same risks, and it is better to make that choice before the first send than after an incident.

The risk you are trying to avoid

Sender reputation is largely tied to the domain. If your main domain builds up negative signals (invalid addresses, messages landing in spam, volume that is too high), it is not only your prospecting emails that suffer. So do your quotes, your invoices, your replies to customers and your application's password reset emails.

A dedicated domain acts as a firewall: if it deteriorates, you replace it, and your day-to-day business is unaffected.

When your main domain is still a good choice

If you send little (a few dozen personalised emails a week) to well-chosen prospects, from one or two named mailboxes, your main domain is perfectly adequate. It has the advantage of age and consistency: a prospect who receives an email from paul@yourbrand.co.uk and types yourbrand.co.uk into their browser lands on your site without any hesitation.

This choice becomes risky as soon as volumes increase, lists are less well targeted, or several people are sending in parallel.

Choosing a secondary domain

The most common practice is to buy one or more domains close to the main one: yourbrand.com if you have the .co.uk, yourbrand-consulting.co.uk, getyourbrand.com, and so on. A few rules:

• stay recognisable: the prospect must be able to make the connection with your brand effortlessly. An unrelated domain looks like an attempt to hide something;
• prefer classic extensions: .com, .co.uk, .io, .co, .eu. Very cheap extensions such as .shop, .online, .store, .fun, .space or .cfd are used heavily by spammers, and filters look at them with more suspicion, even if you do everything else right;
• avoid multiple hyphens and numbers: “your-brand-pro-2.co.uk” does not inspire much confidence;
• buy in advance: a very new domain is inherently suspicious. A few weeks of age, on top of mailbox warmup, make a real difference.

If you have already bought domains with a less recommended extension, there is no need to throw everything away. Measure their inbox placement rate during warmup and only give volume to those that stay above 80 to 90%.

How many mailboxes per domain?

Two to five mailboxes per domain is a reasonable range. Beyond that, you are concentrating risk again. Use named mailboxes, with real first and last names, rather than addresses such as sales@ or info@: they inspire more confidence and get more replies. Each mailbox should have a full sender name, a consistent signature and, if possible, a profile photo.

Calculate the number of mailboxes from your target. A warmed-up mailbox sends 25 to 30 prospecting emails a day. For 600 emails a day, including follow-ups, you need around twenty mailboxes spread across five to eight domains.

Setting up each domain

A sending domain needs the same configuration as your main domain, without exception:

1. MX records to receive replies (a domain that does not accept replies is a very bad signal);
2. an SPF record that authorises the sending server;
3. a DKIM key that is published and actually used for signing;
4. a DMARC policy, at minimum “p=none”.

If those last three points seem unclear, our guide to SPF, DKIM and DMARC explains them step by step. SmartOutbound checks these records every day for all your domains and immediately flags any problem.

Redirecting the domain to your site

This is the most frequently forgotten step, and yet it matters. A curious prospect, or a spam filter, will sometimes visit the domain that emailed them. If they land on a hosting provider's parking page, an error page or an empty page, trust collapses.

Set up a permanent redirect (301 status code) from the sending domain to your main site. Most hosting providers offer this in a few clicks in their domain management area. Check that it works over HTTPS as well as HTTP, with and without “www”.

What not to do

• using a domain to hide your identity: your emails must clearly say who you are, and the signature must point to your real company;
• multiplying domains to get around a content problem: if your messages are perceived as spam, new domains will meet the same fate, just a little later;
• abandoning a domain without understanding the cause: look at bounces, complaints and the content before moving on to the next one.

Our recommendation

For a small team just starting out, two or three secondary domains on .com or .co.uk, close to the brand, with two to three named mailboxes each, redirected to the main site and warmed up for three weeks before the first campaign. Keep the main domain for your day-to-day correspondence and your customers.

SmartOutbound connects to the mailboxes you already own, at any hosting provider, and handles warmup, DNS checks and the distribution of sends across domains. Start with the free trial month to see how your domains perform.