Whoever opens a shared inbox did not personally sign up for anything. A marketing message arriving there is read by someone whose job is handling inquiries, and the spam button is a faster resolution than an unsubscribe link.
Detection is a prefix match rather than a probe, which makes it exact. The address either starts with a known function name or it does not, and there is no inference involved.
For some businesses the exception matters more than the rule. A two-person consultancy where info@ is the only address anyone reads is a real prospect, and a blanket removal deletes them. Small-company data deserves a look before the filter runs.
Legal risk rises with these addresses too. Mailing abuse@ or postmaster@ is a direct route to being reported by the person whose job that is, and those two should be excluded unconditionally.
In transactional contexts the calculation reverses. A billing notice to accounts@ reaches exactly the right desk, and a purchase receipt to orders@ is what the customer asked for.
Sorting 900 role addresses into three piles
Say your business list has 30,000 contacts and 900 of them are role addresses, which is 3%. Don't treat them as one group. Start with the ones that should never get marketing: abuse@, postmaster@, noreply@ and the like. Suppose that's 40 addresses. Drop them from every list.
Next, pull out the general inboxes at very small firms. If your data has a company-size field, filter for info@ and office@ at firms with under ten staff. Say you find 380. At that size the general inbox is often the owner's inbox, so keep these in your marketing sends.
That leaves 480 addresses such as support@ and billing@ at larger companies. Move those to a transactional-only group. They still get the invoices and service notices a billing or support desk expects to see, and they stop getting your newsletter.
Check whether role addresses hurt you, using your own data
You don't have to take the rule on faith. In your email platform, build a segment of addresses that start with info, sales, support, admin, billing, contact, help, office or team. Compare that segment with everyone else over your last five campaigns.
Look at two numbers: complaints and unsubscribes. Open rate matters less here. If the role segment unsubscribes at three times the rate of named contacts, the rule is earning its keep on your list. When the two segments look alike, your audience may be small firms where the shared inbox is one person.
Mind the small numbers. With 900 role addresses, a single complaint is 0.11%, which is already over the 0.1% level that providers watch. One campaign proves nothing, so judge on the total across several.
Be aware that some email platforms refuse role addresses during a bulk import. If your import count comes up short, that's a likely reason.
Related questions
Do role addresses bounce more often?
No. They tend to be stable and long-lived. What they generate is complaints and unsubscribes, which is a different cost.
Which prefixes count as role addresses?
info, sales, support, admin, billing, contact, help, office, team and similar function names, plus abuse and postmaster.
Should small-business lists keep them?
Often yes. At a very small company the role address is frequently the owner's only mailbox.
Are role addresses valid?
Usually, and validity is not the question. The verdict is about suitability for a particular kind of send.