How to Archive Email & Free Up Server Storage

How to Archive Your Emails and Free Up Server Storage

By manageadmin
19 August 2026

Is your mailbox close to its storage limit, or already hitting it? If so, you need to free up server storage. The good news is that you don’t have to delete anything important. Archiving is the answer. It moves your emails off the mail server and onto your own computer. Your emails stay fully accessible in your email program, so nothing is lost. They just no longer count towards your server storage quota.

How to Archive Your Emails and Free Up Server Storage

A few things worth knowing before you start:

Archiving is not the same as deleting. Your emails stay safe, searchable and readable. Instead of sitting on the server, they simply live locally on your device.
The Sent folder is usually the biggest space hog that people forget about. Every email you’ve ever sent sits in there, including ones with large attachments. Yet it rarely gets cleaned up.
Any folders you’ve created yourself — project folders, client folders, an “Invoices” folder — live on the server too. As a result, they are just as easy to forget during a clean-up.
Your Deleted Items / Trash folder counts too. Deleting an email usually just moves it into the Trash (or “Deleted Items”) folder. There it keeps using your server storage until it is permanently removed. So if that folder is never emptied, months of deleted mail can quietly pile up. In fact, it can push you over your quota all by itself. Empty it regularly, then, not just once during a clean-up.
“Archive” doesn’t always mean “off the server”. Several mail programs have an Archive button or swipe gesture — Apple Mail, the newer Outlook and most phone apps. However, it just moves messages into a folder called Archive inside your account. That folder still sits on the mail server. Because it uses the same storage as your Inbox, it won’t free up any space. Instead, you have to move mail into a local folder on your own computer. Depending on the program, that folder is called “On My Mac”, “On My Computer” or “Local Folders”, as described below.
Archiving works best with desktop email programs such as Outlook, Apple Mail and Thunderbird, because they can save a genuine local copy. Pure webmail — logging into a browser only — can’t do this. For that situation, see the note at the end.
If you use IMAP (most hosted mailboxes do), archiving only frees up space on the server itself — it doesn’t sync. Once an email is archived into a local folder on one device, it disappears from your other devices and from webmail. That is because it is no longer stored on the server at all. It is still safe and readable, but only on the device you archived it to. So if you check email on your phone, laptop and webmail, decide up front which one device will “own” the archive. A work desktop is usually the sensible choice. Then keep a note of where it lives.

Already Full? Use Webmail to Get Back Under Your Limit First

When a mailbox is completely full, desktop email programs often start misbehaving before you get a chance to archive anything. You might see send failures, an “unable to copy to Sent” error, repeated password prompts, sync errors, or the program simply freezing as it tries to reconcile with the server. As a result, trying to archive from a program in that state can be slow or unreliable.

The quickest way out is to bypass your email program and log in to webmail:

In any web browser, go to https://tekwizard.net/webmail and sign in with your full email address and password.
Webmail always shows the true state of what is on the server, so you can act straight away. If your webmail app lets you sort by size, do that, then clear space from the usual culprits:
- Trash / Deleted Items — empty it completely.
- Junk / Spam — empty it too.
- Sent — delete or move out the oldest large items.
- Large attachments anywhere — a handful of these often frees more space than hundreds of ordinary emails.
Once you are comfortably back under your limit, close and reopen your normal email program. It should reconnect cleanly, and you can then do a proper archive (steps below) so the problem does not come back.

If webmail will not load either: repeated failed logins can get your whole internet connection temporarily blocked. This is usually an old phone or laptop still trying a former password. Our mail server’s firewall does the blocking, and it stops webmail working from that network as well. So try again from a different connection — for example, your phone on mobile data instead of Wi-Fi. If it still will not connect, get in touch and tell us your current IP address. Search the web for “what is my IP”, then send us the number so we can clear the block.

For a full run-through of webmail — logging in, working out where a problem is, and finding the built-in tools — see our guide to using webmail.

Below are step-by-step instructions for the most popular email programs.

Microsoft Outlook (Windows desktop)

Outlook has a built-in Archive feature that moves emails into a local .pst file stored on your computer.

Go to File → Tools → Clean Up Old Items (or File → Info → Cleanup Tools → Archive, depending on your Outlook version).
Choose “Archive this folder and all subfolders” and select your account at the top of the folder tree, so every folder is included.
Set a date — e.g. “Archive items older than 6 months” — and choose where to save the archive file (the default location is fine for most people).
Click OK. Outlook will move matching emails out of the server mailbox and into the local archive file.

Don’t forget:

When you archive from the account root, Outlook includes the Sent Items folder automatically. Still, double-check it’s ticked, because some Outlook versions leave it out by default.
Any custom folders you’ve created appear indented under your inbox. They are also covered when you archive from the top level. Just make sure you haven’t selected only “Inbox”.

Afterwards, you can view archived mail any time via File → Open & Export → Open Outlook Data File. Alternatively, it will usually show up automatically as an “Archives” folder in the left-hand pane.

Microsoft Outlook (Mac)

Ignore Tools → Run Rules — that is not the one you need. Instead, go to Organize → (right-click a folder) → Archive. Alternatively, open Tools → Preferences → Sync and simply drag old emails into a local “On My Computer” folder.
Create a local folder first: right-click On My Computer in the sidebar → New Folder. Name it something like “Archive 2024”.
Drag emails (or whole folders, including Sent Items and any custom folders) from your account into that local folder.

Outlook for Mac doesn’t use the same .pst archive system as Windows. Because of that, dragging into an On My Computer folder is the reliable method. It works for Sent Items and custom folders exactly the same way as your Inbox.

Apple Mail (macOS)

Apple Mail lets you create “On My Mac” folders that live only on your computer, not on the server.

In the sidebar, right-click On My Mac and choose New Mailbox. Give it a clear name, e.g. “Archive”.
Select the emails you want to move — you can select a whole folder’s worth using Edit → Select All while that folder is open.
Drag the selected emails onto your new On My Mac mailbox (or right-click → Move to → choose the mailbox).

Important: don’t use Apple Mail’s Archive button or the swipe-to-archive gesture for this. Those move messages into an Archive mailbox that is still part of your account on the server. So they don’t reduce your storage at all. Only moving mail into an On My Mac folder actually frees up space, as in the steps above.
Don’t forget:

Open your Sent mailbox and repeat the same steps — Apple Mail treats it as just another folder, so it’s easy to skip.
Any custom mailboxes you’ve created under your account (shown indented in the sidebar) can be dragged into “On My Mac” the same way, either individually or in bulk.

Once moved, mail in “On My Mac” folders no longer takes up space on the server, but stays fully visible and searchable in Apple Mail.

Mozilla Thunderbird

Thunderbird has a dedicated Archive feature, plus the option of local folders.

Using the built-in Archive button:

Select the emails (or a whole folder) you want to archive.
Click Archive in the toolbar, or press A.
Thunderbird then moves them into an Archives folder, organised automatically by year. However, check where that folder actually lives. For IMAP accounts it often defaults to the server, which won’t save space. So in Account Settings → Copies & Folders → Message Archives, set the archive location to Local Folders. Then archived mail comes off the server.

For folders Archive doesn’t cover automatically (Sent and custom folders):

Right-click your account name → New Folder, and make sure “Local Folders” is selected as the location (not your IMAP account) — this creates a folder that stays on your computer.
Open your Sent folder, select all, and drag the messages into your new Local Folder.
Repeat for any custom folders you’ve created under the account.

Don’t forget: Thunderbird’s one-click Archive button generally only archives the folder you’re currently viewing. So also open Sent and any custom folders individually, then archive or drag those across too.

Mobile Mail Apps (iPhone/iPad Mail, Android Gmail app, Samsung Email)

This is the trickiest category. Most mobile mail apps don’t store a true local copy the way desktop programs do. Instead, they are really just a window into the server. So on mobile, “archiving” usually just moves the email to an Archive folder that’s still on the server. As a result, it won’t reduce your storage usage.

Recommendation: for genuine storage savings, do your archiving from a desktop email program such as Outlook, Apple Mail or Thunderbird, using the steps above. Afterwards, your mobile app will simply show whatever’s left on the server.

A Note on Webmail-Only Access

Perhaps you only ever check your email by logging into a website, rather than using a program like Outlook, Apple Mail or Thunderbird. If so, there’s no way to “archive” mail off the server from the browser alone. Everything you see in webmail is the server. In that case, you have three options:

Set up a desktop email program (even just Thunderbird, which is free) to connect to your mailbox via IMAP, then use the archiving steps above.
Delete what you genuinely don’t need — old newsletters, notifications, and duplicate attachments are usually the quickest wins.
Ask us to increase your mailbox storage if archiving and clean-up still aren’t enough for how you use email day to day.

Quick Checklist

Whichever program you use, make sure you cover:

✅ Inbox
✅ Sent (often the biggest and most overlooked folder)
✅ Any custom/self-created folders
✅ Deleted Items/Trash — emptying this folder afterwards also frees up space, since deleted emails often still count against your quota until permanently removed

Remember: once you archive mail on IMAP, it is local to that one device only. It won’t appear on your phone, your other computers or webmail any more. So pick the device you archive to on purpose, rather than using whichever one you happen to be on that day.

If you’d like a hand walking through this on your specific setup, or want us to check how much space archiving has actually freed up on the server, get in touch and we’ll take a look.