The Email Verified as Valid but the Person Left the Company: Why It Happens and What to Do

Email verification tells you whether a mailbox accepts mail. It doesn't tell you whether the person who used to read it still works there. When someone leaves a company, the company decides what happens to their address, and many keep it alive for a while: forwarded to a manager, turned into a shared mailbox, or simply left open. In all of those cases a verifier correctly reports the address as able to receive mail, and your message lands in front of someone who never heard of you, or no one at all. That isn't a verification error. It's a different question, and it needs a different process.

What a mailbox check can and can't see

A verifier connects to the recipient's mail server and asks, without sending a message, whether it would accept mail for the address. Our how it works page describes exactly what SimpleVerifier checks.

A mailbox check can tell you	It can't tell you
The domain receives mail	Whether the person still works there
The server accepts or refuses this address	Who reads the mailbox now
The domain accepts every address (catch-all)	Whether anyone reads it at all
The address is disposable or a role address	Whether mail is forwarded somewhere else

So "valid" means "this server will take mail for this address today". For a leaver whose mailbox was kept, that's true.

What companies do with a leaver's mailbox

Both big business email platforms give admins several options when someone leaves. Each one looks different from the outside.

Microsoft 365

Microsoft's own guide for admins, Forward a former employee's email or convert to a shared mailbox (updated 30 October 2026, read 2 November 2026), offers two main paths:

• Convert to a shared mailbox. "All of the existing email and calendar are retained in a shared mailbox that several people can access." Microsoft notes that a shared mailbox under 50 GB needs no licence, so it is a cheap option and an easy one to leave in place indefinitely.
• Forward the mail. "If you set up email forwarding, only new emails sent to the former employee's email address are sent to the current employee." Microsoft says not to delete the account: "The account needs to be there to anchor the email forwarding or shared mailbox."

Google Workspace

Google's admin help on deleting or removing a user (updated 26 October 2026, read 2 November 2026) gives admins the option to redirect incoming messages to another address before deleting the account, to reassign the address to another user, or to suspend or archive a user to keep their data. On deletion, Google says: "Twenty days after a user's account is deleted, their email address is removed from Google Workspace."

What each choice looks like to you

What the admin did	What a verifier sees	What happens to your email
Left the account open	Accepts	Sits unread, or someone checks it occasionally
Converted to a shared mailbox (Microsoft)	Accepts	Read by whoever has access, often a manager or team
Forwarded to a colleague	Accepts	Arrives in a stranger's inbox
Redirected or reassigned the address (Google)	Accepts	Arrives with whoever now owns it
Set an auto-reply saying they've left	Accepts	You get a reply naming a contact, if you read it
Deleted the account	Refuses, once the deletion takes effect	Hard bounce
The domain accepts all addresses (catch-all)	Accepts every address	Unknowable from outside

Only the deletion row produces a bounce, and that is the one case a verifier catches. Everything else needs other signals.

The signals that someone has left

Signal	Where it shows up	Reliability
An auto-reply saying "no longer with", "has left" or "is no longer at"	Your replies inbox	High
An auto-reply naming a different contact	Your replies inbox	High, and gives you the successor
A new job on their public profile	LinkedIn or the company's team page	High, but needs checking
A hard bounce weeks after a valid check	Your bounce log	Certain, but late
A role change in your CRM data	Enrichment or a data provider update	Medium; databases lag
No opens or replies across a whole sequence	Campaign stats	Low; many people simply don't reply

Auto-replies are the most useful and the most ignored. Many sequencers file them as "out of office" and move on. Search your replies for the leaver phrases and treat each one as a data update.

A process that keeps a B2B list current

1. Verify close to the send

Data that was fine three months ago may not be now. Verify each list shortly before the campaign starts, not when you bought or built it. This catches addresses whose mailboxes were deleted in the meantime. Our B2B contact data decay guide covers how quickly lists age, and the email list decay calculator estimates it for your list.

2. Read auto-replies for departures

Set up a filter for "no longer with", "has left", "left the company", "is no longer employed" and similar phrases in the languages you send in. For each match:

• Mark the contact as left in your CRM and remove them from active sequences.
• If a successor is named, add them as a new lead, and verify their address before sending.
• Don't keep sending the original sequence to the old address. Whoever reads it now didn't ask for it.

3. Re-check before follow-ups on long sequences

If a sequence runs for weeks, the person can leave mid-sequence. Our guide to follow-up emails bouncing explains why later steps bounce more than the first, and how to re-check between steps.

4. Replace, don't just remove

A leaver usually has a successor. Find who now owns the role, work out the address from the company's pattern with the email format finder, generate candidates with the email permutator, and verify the result.

5. Treat catch-all domains with extra care

On a domain that accepts every address, a verifier can't tell a current employee from a leaver, or even from a made-up name. Our guide to catch-all emails covers how to decide whether to send.

6. Feed bounces back

When a hard bounce arrives on an address that checked valid, it's usually a deletion that happened after the check. Suppress it, and if many addresses at one company bounce together, read bounces from one domain, because that pattern often means a migration, not a wave of leavers.

Why this matters for deliverability

Email that reaches a forwarded or shared mailbox is mail to someone who didn't expect it. Those recipients have no reason to want it, so they ignore it or report it more readily than the person you meant to reach would. A few won't hurt you. A list full of them, sent at volume, adds to the complaints and non-engagement that mailbox providers use to judge your domain. Keeping the person current, not just the address, protects the domain as well as the reply rate.

Where SimpleVerifier fits

SimpleVerifier answers the mailbox question: a live check on each address that returns safe to send, send with care, check again later or do not send, with the reason. It catches addresses whose mailboxes were deleted after your data was collected, and it labels catch-alls as risky rather than guessing them valid. It can't tell you who reads a mailbox, which is why the process above matters. If you need the successor's address, the email finder on Pro takes a name and a company and returns a verified address.

The first 100 checks are free with a Google sign-in on the verify page. Pro is $39 a month with the first 100,000 checks a month at full speed, then slower, never cut off, and includes the email finder. See pricing.