A mailbox per client: how bookkeepers keep several accounts straight

Bookkeepers manage multiple email accounts best by keeping three kinds of address apart. Your firm address is yours, and free role aliases on it catch documents and alerts. A mailbox a client gives you stays the client’s account: you sign in to it on its own, read it on a set rhythm, and reply from it. You don’t forward it into your own inbox. That one habit keeps each client’s mail in that client’s account, so nothing mixes and nothing is left behind when a client moves on.

Most of your clients will never give you a mailbox. A few will, usually the ones whose vendors already write to books@ or ap@ at their business. Five of those alongside your own address is a normal desk. This page covers how to read them all without missing the one message that mattered.

Multiple email accounts for bookkeepers: three kinds, three rules

Here are the addresses a bookkeeper usually ends up with.

The first two rows are one account. Role addresses are aliases, and they land in the same inbox. Google’s admin help says you “can add up to 30 email aliases for each user at no extra cost” (Google Workspace Admin Help). Microsoft lets an admin “create up to 400 aliases for a user” with no extra fees (Microsoft Learn). Which aliases to run, and what each one catches, is set out in email management for bookkeepers.

The third row is the subject of this page. It’s a separate account on someone else’s domain, and three rules keep it straight:

1. It stays the client’s. The client created it, the client pays for it, and the client can take it back.
2. It’s read where it lives. Sign in to it directly, or connect it to a reader that leaves the mail in place.
3. You reply from it. Vendors and the bank already know that address. An answer from your own address starts a second thread they don’t recognize.

Why a client hands you a mailbox

It’s rarely your idea. A client gives you a mailbox because their business already sends things to one.

• Vendors bill it. Twenty suppliers have ap@theirbusiness.com on file. Changing that means twenty emails.
• The bank and the software notify it. Bank feed alerts, payroll run confirmations and accounting software notices all go to the address on the account.
• It outlives you. If the client changes bookkeepers, the next one gets the same address and its whole history.
• It looks like the business. A vendor asking “what’s this short payment?” gets an answer from books@ at the company they billed.

All four are good reasons. They’re also why the mailbox should stay theirs. Its value is that it belongs to the business and keeps working whoever does the books.

Four ways to read a client’s mailbox

There are four common setups. Two of them are getting harder in 2026.

Forwarding

Forwarding feels simplest, and it’s the one to avoid. Every message the client’s business receives becomes a copy in your firm’s mailbox. When the client leaves, those copies stay with you. Replies go out from your own address, so a vendor sees a stranger answering their invoice.

It often won’t work anyway. Microsoft changed the default for external auto-forwarding in 2021. It’s now “Off - Forwarding is disabled” for new Microsoft 365 organizations and for existing ones that weren’t using it (Microsoft Learn). A blocked forward bounces back to the sender with a 5.7.520 “Access denied” error. So the vendor’s invoice bounces, and nobody tells you.

Pulling it into Gmail

Gmail used to fetch other accounts into one inbox. Google is retiring that:

Gmail will no longer support checking emails from third-party accounts through POP.

Google’s help page says the feature stopped taking new users after the first quarter of 2026, and existing users keep it “until January 2027” (Gmail Help). A second change goes with it. Gmail’s “Send as” for third-party addresses goes away fully in January 2027 (Gmail Help). “Send as” for other Google-hosted addresses keeps working.

If a client’s mailbox reaches you this way today, it has about three months left. Now is a calm time to move it, rather than the first week of January.

Signing in to each one

This is the clean setup, and it’s the one most bookkeepers land on. Each client mailbox is its own sign-in, often in its own browser profile. Google says you can “sign in to multiple accounts at once” and switch between them without signing out (Google Account Help).

The cost is attention. A mailbox you open on Tuesdays and Fridays holds Wednesday’s message until Friday.

One reader for all of them

A mail app or an inbox layer can show several accounts in one place while the mail stays in each account. That fixes the attention problem without the copying problem. The catch is permission. A Google Workspace admin can mark any third-party app “Trusted”, “Limited” or “Blocked” (Google Workspace Admin Help). Ask the client before you connect their mailbox to anything.

What the client should set up for you

Two things that sound right don’t work across businesses.

• A shared mailbox on Microsoft 365. Microsoft says plainly that “You can’t give people outside your business, such as people with a Gmail account, access to your shared mailbox” (Microsoft Learn).
• Gmail delegation on Google Workspace. On a work account, Google says “you can only add other people or groups in your organization as your delegate” (Gmail Help).

So the setup that works is a user account in the client’s own system with your name on it. Ask for one of these:

• A named account, such as jordan.books@theirbusiness.com, so the client can see who sent what.
• A role account, such as books@theirbusiness.com, if they want the address to outlive you.
• Their second factor on your device, with them as the recovery contact. You can sign in without texting them every morning. They can still lock you out in one step.

Write down which of these each client chose. It saves a phone call on the day something needs resetting.

Keeping one client’s mail away from another’s

Mixing client data is rarely dramatic. It’s a statement saved to the wrong folder, or a reply sent from the wrong window. A few habits cover nearly all of it.

• Reply from the mailbox the message arrived in. A vendor’s question to books@ gets its answer from books@.
• One browser profile per client mailbox. The profile’s name and color tell you whose mail you’re in before you type.
• Files go to that client’s folder the day they arrive. Where each one goes next is in receipts and statements.
• Never forward between clients. If two clients share a vendor, each gets their own copy from the vendor.
• Your notes stay in your own system. A note about Client A’s categorization belongs in your files, not in a draft in Client A’s mailbox.

A payment change needs one extra step. A client mailbox is where “please update our bank details” arrives, and it’s where business email compromise starts. The FBI’s Internet Crime Complaint Center put exposed losses from it at about $55.5 billion between October 2013 and December 2023 (IC3). Its advice is short:

Use secondary channels and/or two-factor authentication to verify requests for changes in account information.

For a bookkeeper, that means calling the vendor on a number you already had before you change anything in the books.

A Monday across five mailboxes

Here’s an ordinary Monday for a bookkeeper with three client mailboxes, written out as the mail arrived.

Read one mailbox at a time and Monday goes like this. Your own address gets the morning. Marlow Roofing gets its look on Tuesday. Greenleaf Cafe’s mailbox waits until Thursday, when the cafe owner asks whether the vendor got paid.

Read together, each line shows up the morning it arrives. The vendor’s bank change sits next to everything else, and you call before Wednesday’s payment run. What a morning read should put first is in the morning read. The $1,180 charge is in explaining a charge.

Not missing what lands in the mailbox you open last

If you keep separate sign-ins, give every mailbox a schedule. It’s the mailbox nobody scheduled that holds the late statement.

• Daily for any mailbox that gets bills. Payment runs don’t wait for your Friday.
• Twice a week for the quiet ones. Pick the days and keep them.
• The week before close, every mailbox, every day. That’s when the missing statement turns up.
• A one-line note per mailbox. “Gets supplier bills, bank alerts, the payroll provider.” You’ll know what to look for in ten seconds.

Searching across mailboxes is the other gap. A search in one account never finds a receipt in another. When you need last March’s statement, start in the mailbox the bank sends to. Finding a client’s statement fast covers the searches.

When the client leaves, or you do

A client mailbox makes leaving easy, as long as you do it in order.

1. Answer or hand over every open thread. Write a short note of what’s waiting on whom.
2. Remove the mailbox from any app you connected it to. Do it from your side, then ask the client to check theirs.
3. Hand back the second factor. Move it to the client’s phone, or ask them to reset it.
4. Ask the client to change the password. Then confirm you can’t sign in.
5. Check your own inbox for stragglers. Anything that was forwarded in the past gets moved to your client file or deleted under your retention policy.

If the mailbox stayed the client’s all along, step five takes a minute. If it was forwarded into yours, it can take an afternoon.

How Point reads several mailboxes at once

Point connects Gmail and Microsoft 365 accounts. Adding one is a sign-in, with no forwarding rules to set up. The mail stays in each account, so a client’s mailbox stays the client’s.

Here’s what Monday looks like with your own address and a client’s mailbox connected.

• One feed. Mail from each account is sorted together into Now, Later and Other. Greenleaf’s vendor email sits under Now at 11:30, next to your own.
• Each mailbox stays in step. Point writes the same three names back into each account, as labels in Gmail and categories in Outlook. The client sees those labels too, so mention them when you ask.
• Replies wait for you. Point can draft the answer. By default nothing goes until you’ve read it and pressed send. Send one test reply from each connected account on the first day and check the From line.

Two things are worth knowing before you connect a client’s mailbox. First, it’s the client’s call, and their admin may need to allow the connection. Second, Point keeps a line between businesses you run. It doesn’t seal one client’s mail off from another’s inside your own firm. Each connected mailbox is still its own account, and the habits above still apply. Keeping one business isolated from another sets out exactly where that line runs. Everything else Point does is on the benefits page.

The connections themselves are in connecting Gmail and the Outlook path.

When separate tabs are the better setup

Sometimes the plain setup is the right one.

• One or two client mailboxes. Two browser profiles and a schedule may be all you need.
• A client who says no. Some clients don’t want their mailbox connected to anything. Sign in directly and keep to the schedule.
• A mailbox on another host. If the client’s mail isn’t on Gmail or Microsoft 365, it stays in its own tab or a desktop mail app.

The setup matters less than the rule underneath it. Each client’s mail stays in that client’s account, and you read every mailbox on a schedule you keep.

Common questions

Are you allowed to have multiple email accounts?

Yes. Google says you can sign in to several Google Accounts at once and switch between them. A client can create an account for you on their own domain, the same way they’d create one for an employee. Two limits apply. A Microsoft 365 shared mailbox can’t be opened by someone outside the client’s business. A Google Workspace mailbox can’t be delegated outside the client’s organization. Ask the client for a user account in your name instead.

Should I forward a client’s mailbox into my own inbox?

It’s better not to. Forwarding copies every message into your firm’s account, and the copies stay when the client leaves. Your replies come from your own address, which vendors don’t recognize. Microsoft 365 also blocks external auto-forwarding by default for most organizations, so mail can bounce without anyone noticing.

What is the most hacked email provider?

There’s no reliable public ranking. The largest providers see the most attacks because they hold the most accounts. What matters for a bookkeeper is each account’s own protection: a strong password and a second factor on every mailbox, yours and the client’s. The attack that costs bookkeepers money is a fake payment change sent to a mailbox they read. Verify every one by phone, on a number you already had.

Why are people moving away from Gmail?

Reasons vary, and privacy and price come up often. For people who read several accounts, there’s a concrete one in 2026. Google is ending POP collection of other accounts into Gmail. “Send as” for third-party addresses ends in January 2027. Anyone using Gmail as the hub for a non-Google client mailbox has to change that setup by then.

What is the 3 email rule?

People use the name for two different habits. In one, a thread that passes three emails without settling something is your cue to call. In the other, you keep three addresses: personal, work and a spare for sign-ups. The first is useful for categorization queries that go in circles. The second is roughly the firm-address-plus-aliases setup at the top of this page.

Can I use my own address for some client mail and their mailbox for the rest?

Yes, and most bookkeepers do. The client and their staff write to your own address. Vendors, the bank and their software write to the mailbox the client gave you. Answer each from the address it came to, and the two stay clear.