My mailbox is full. How do I free up space?

How do I free space on my phone?

1. iPhone or iPad: open Settings, General, iPhone Storage (or iPad Storage). The list shows which apps use the most space. Photos and videos are usually bigger than Mail.
2. Android: open Settings, then Storage (the name varies by make). Clear large downloads, videos and unused apps first.
3. If Mail is the big item, delete old messages with large attachments after saving any attachment you need. With IMAP, deleting on the phone deletes from the server too, so be sure.

Expected result: the storage warning goes away, and new mail keeps arriving.

Where is the “full” warning coming from?

Where you see it	What it usually means	What to do
iPhone or iPad: “Storage Almost Full”	The device is short of space. Mail stores copies of messages and attachments on it.	Free space on the device (see below).
Android phone: storage warning	Same: the phone is short of space.	Free space on the phone.
Outlook on a computer: data file or disk space warning	Outlook keeps a copy of your mail in a data file on the computer, and that file or the disk is getting large.	Free disk space, or archive old mail (see below).
A sender’s bounce says “mailbox full” or “over quota”	Not expected on E-3’s server.	Ask for the bounce text and call E-3.
The warning is on a Microsoft 365 or Google mailbox	That service has its own limit.	Follow that provider’s guide, or ask us.

The short version

• E-3’s SmarterMail server has no mailbox size limit. A “full” warning nearly always means your phone or computer is short of space.
• Senders getting “mailbox full” bounces from an E-3 address? Call 814-399-4655.

How do I keep old email without filling my computer?

Your mail is safe on the server, so you don’t need to save it elsewhere just to keep receiving. If your computer is short of space, or you want a separate copy:

• Outlook: older mail can be kept in an Outlook data file. Microsoft explains how Outlook data files work.
• Mac Mail: Apple shows how to export a mailbox with Mailbox, then Export Mailbox.

Before any bulk delete:

1. Make the copy, and check that it opens.
2. Back that copy up. Once mail lives only on one computer, it’s lost if that computer fails.
3. Only then delete from the server.

How do I tidy my mailbox in webmail?

Not required, but it makes mail easier to find. Sign in at mail.e3webmail.com. Help signing in is in reset your email password or sign in to webmail. Screens can vary by SmarterMail version, so labels may differ slightly from the steps below.

1. Empty Junk Email after a quick look for anything real. SmarterTools’ folder guide warns that emptying a folder deletes those messages permanently.
2. Empty Deleted Items, after checking nothing was deleted by mistake.
3. Sort by size in your Inbox and Sent Items to find big old attachments. Save what you need, then delete.
4. SmarterMail also has a per-user Disk Usage report, described in SmarterTools’ disk usage guide. Your version may place it elsewhere, or it may be turned off.

Is there a size limit on my E-3 mailbox?

No. E-3 doesn’t set a mailbox size limit on its mail server, so you don’t need to delete mail to keep receiving it. You can still tidy up if you like, but it won’t change whether mail arrives.

Why does this matter?

Clients sometimes delete years of mail because a warning said “full”, when the real problem was a phone short of space. Knowing where the warning comes from saves your mail and your time. And if a customer says their message to you bounced, that’s worth a quick call, because the cause is something other than space.

What are the common mistakes and edge cases?

• Deleting mail to fix a phone warning. With IMAP, deleting on the phone deletes from the server for every device. Free other space first.
• Removing the account from a device to save space. It frees space on that device only, and can lose mail stored only there (for example a POP account or “On My Computer” folders). See folders and sync.
• Phone and webmail disagree. Trust webmail. That’s what the server holds.
• You’re on Microsoft 365. Mailboxes there have a limit: up to 100 GB on the Business plans (Microsoft raised Business plans from 50 GB in 2026). Microsoft’s mailbox storage limits guide explains what happens when one fills, and its Exchange Online limits page lists sizes by plan.

What if this didn’t work?

1. Check which service the address is on. See E-3 email: start here.
2. Ask a sender for the error code and explanation line from the bounce they got back (not the whole message). It names the exact reason, which may not be space at all.
3. Call 814-399-4655 with your email address and roughly when the bounces started. See why am I not receiving email for other causes.

How does E-3 handle this?

E-3’s server has no mailbox size limit, so we don’t ask you to delete mail to stay under one. If a sender gets a “mailbox full” bounce from an E-3 address, send us the bounce text. Call 814-399-4655 or email support@e3help.me. Replies usually come within one business day.

Related questions

• Why am I not receiving email?
• Folders and sync on E-3 email
• Can you move my email to Microsoft 365?