// BTINTERNET SMTP FIX
Can’t send BTinternet email from new Outlook?
Your BTinternet email downloads fine but every message you try to send just sits there or bounces back. It’s almost always the outgoing server — here are the exact settings and the quickest way to get sending again. Rated 4.9 on Google.
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/01 — QUICK ANSWER
Can’t send BTinternet email from new Outlook? Start here
If your BTinternet email receives fine but won’t send in new Outlook, the outgoing (SMTP) server is nearly always the cause. The correct outgoing settings are mail.btinternet.com on port 465 with SSL, with authentication switched on and your full email address as the username — and because new Outlook often won’t let you edit those once an account is added, putting them right usually means removing the account and adding it back with the right details. Sending typically fails because the ‘server requires authentication’ box is unticked, or the port and encryption don’t match.
Receiving and sending use two different connections, which is exactly why one can work while the other doesn’t — you can read new mail through the incoming (IMAP) server even when the outgoing server is misconfigured. Below you’ll find the precise settings BT publishes, the common reasons sending breaks, and a step-by-step fix — plus an honest note on new Outlook’s known quirks with BT accounts. If you’d rather not touch server settings at all, call us on 01202 775566 and we’ll sort it remotely while you watch.
At a glance
| Most common cause | Wrong outgoing (SMTP) server settings — usually authentication switched off, or the port and encryption don’t match. |
|---|---|
| Correct SMTP settings | mail.btinternet.com, port 465 with SSL, authentication on, and your full email address as the username. |
| DIY first step | Remove the BT account and re-add it using advanced IMAP setup — new Outlook usually won’t let you edit an existing account. |
| If port 465 fails | Re-add the account using port 587 with STARTTLS instead — never mix the port and encryption pairings. |
| Left BT broadband? | Free Basic email is webmail-only and can’t send or receive in Outlook at all — no settings change will fix that. |
| Can it be fixed remotely? | Yes — most are sorted in one short remote session while you watch, and it’s no fix, no fee. |
// NEED THIS FIXED RIGHT NOW?
Skip the DIY — call 01202 775566 and we can be looking at your screen within minutes. You watch everything we do, and most problems on this page are fixed in one short remote session. (Mon–Fri, 9am–5pm.)
/02 — THE RIGHT SETTINGS
The correct BTinternet outgoing (SMTP) settings
These are the settings BT publishes for any email program, including new Outlook. Use them exactly — a single wrong digit stops sending.
- Outgoing (SMTP) server: mail.btinternet.com
- SMTP port: 465 with SSL/TLS (SSL enabled, not STARTTLS)
- Authentication: required — the same username and password as your incoming server
- Username: your full BTinternet address, e.g. yourname@btinternet.com (or @btopenworld.com / @talk21.com)
- Password: your BT email password — not a BT broadband account PIN
For completeness, incoming mail is mail.btinternet.com on port 993 with SSL (IMAP). If port 465 won’t send, port 587 with STARTTLS usually works as an alternative outgoing port — you’d enter one or the other when you add or re-add the account. These are the same details you’d use when the account won’t add in the first place; if you’re stuck at that earlier stage, see our guide on BTinternet email that won’t add to new Outlook.
/03 — WHY IT FAILS
Why BTinternet sending breaks in new Outlook
Sending breaks for a handful of predictable reasons. Working through them in order usually finds the culprit:
- Authentication is switched off. BT rejects any message where the outgoing server isn’t authenticated, which typically shows as a 530 error. The ‘my outgoing server requires authentication’ setting must be on, using the same login as your incoming mail.
- Wrong port and encryption pairing. Port 465 needs SSL; port 587 needs STARTTLS. Mixing them — 465 with STARTTLS, or 587 with SSL — fails silently and leaves mail sitting in the outbox.
- You’ve left BT Broadband and dropped to free Basic email. When you leave BT, you have 60 days to move your mailbox to BT’s paid Premium Mail or link it to another BT Broadband line; otherwise it becomes free Basic email, which only works through BT webmail in a browser and can’t send or receive in Outlook at all. If that’s happened, no settings change will fix Outlook — you’d need Premium Mail or a linked BT line to restore email-app access.
- New Outlook’s IMAP quirks. Microsoft is still maturing new Outlook’s handling of third-party IMAP accounts — it won’t even let you edit the server settings once an account is added — so some BT users can receive but not send until the account is removed and re-added.
If your messages are visibly piling up, our notes on email stuck in the Outlook outbox and Outlook repeatedly asking for your password cover two of the most common symptoms.
/04 — THE FIX
How to fix it, step by step
Here’s the reliable order to fix it in new Outlook. Because new Outlook usually won’t let you change the outgoing server on an account that’s already set up, the dependable fix is to re-add the account with the right details.
- Open new Outlook, click the Settings gear (top right), then Accounts, then Email accounts, and select your btinternet.com account.
- Click Manage. If new Outlook happens to show editable IMAP and SMTP settings, set the outgoing server to mail.btinternet.com, port 465 with SSL, and confirm authentication is on. For most BT accounts, though, there’s nothing editable here — that’s a known Microsoft limitation, not something you’ve done wrong.
- So remove the account and add it again — choose ‘Show more options’ (advanced setup) and pick IMAP so you can type the servers yourself.
- Enter incoming mail.btinternet.com, port 993, SSL and outgoing mail.btinternet.com, port 465, SSL, tick that the outgoing server requires authentication, and use your full email address and BT email password.
- Send a test message to yourself. If it won’t send on port 465, re-add using port 587 with STARTTLS instead.
New Outlook’s menus shift between updates, so the exact wording may differ slightly on your version — but the server values above don’t change. Take a screenshot of any error message before you make changes; the code (such as a 530, or a timeout) tells us exactly which part is failing.
/05 — STILL STUCK
If it still won’t send
Sometimes new Outlook simply won’t co-operate with a BT IMAP account, even with perfect settings. That’s a genuine, documented limitation rather than anything you’ve done wrong — several BT users find sending works immediately in Classic Outlook while new Outlook still refuses.
If you need to send today, the quickest workaround is to switch back: our guide on going back to Classic Outlook walks through the toggle. Classic Outlook gives you full manual control of the SMTP port and encryption, which is exactly what a stubborn BT account needs. You can also send from BT’s own webmail at bt.com in the meantime — that bypasses Outlook entirely and confirms your mailbox itself is healthy.
One caveat: if webmail works perfectly but no email app will send, and you’ve left BT Broadband, you may be on BT’s free Basic email, which is webmail-only by design — Outlook can’t use it until you move to Premium Mail or link the mailbox to a BT line. And if sending fails everywhere, webmail included, then the problem is the mailbox or BT account, not Outlook, and only BT can restore it. Our wider Outlook not sending emails guide covers the non-BT causes too. When you’ve tried the settings and you’re still stuck, that’s the point to hand it over to us.
/06 — GET HELP
When to call us — and how we fix it
Most BTinternet sending problems are a five-minute fix once you know it’s the outgoing server — but if you’d rather not poke around in server settings, that’s exactly what we’re here for. 365 Techies is a family-run team in Kinson, Bournemouth, trading since 1995 with a 4.9-star Google rating, and we help people with fiddly email set-ups every week.
We work remote-first across the UK, so we can usually connect to your computer the same day (Monday to Friday, 9am to 5pm) and get sending working while you watch — no need to bring anything in. For customers in Bournemouth, Poole, Christchurch and across Dorset we also offer home visits and collection. Everything is no fix, no fee, so if we can’t get your BT email sending, you don’t pay.
Call us on 01202 775566, text 07520 615332, or see our email support page. Have your BTinternet address to hand and, if you can, a photo of the error — it gets us to the fix faster.
FAMILY-RUN SINCE 1995 · ★ 4.9 ON GOOGLE · 200+ COMPUTERS UNDER OUR CARE · NO FIX, NO FEE · SAME-DAY REMOTE SUPPORT
// GOOD QUESTIONS
Frequently asked
What are the BTinternet outgoing (SMTP) settings for new Outlook?
Use mail.btinternet.com as the outgoing server on port 465 with SSL, with authentication switched on. Your username is your full BTinternet address (for example yourname@btinternet.com) and the password is your BT email password. If port 465 won’t send, port 587 with STARTTLS usually works as an alternative.
Why does my BTinternet email receive but not send?
Receiving and sending use separate connections, so incoming mail (IMAP) can work perfectly while the outgoing (SMTP) server is wrong — usually because authentication is off, or the port and encryption don’t match. The outgoing server should be mail.btinternet.com, port 465 with SSL, authentication on. In new Outlook you often can’t edit that on an existing account, so the fix is normally to remove the account and add it back with the correct details.
I get a 530 error when I try to send — what does it mean?
A 530 response from BT means the outgoing server rejected your message because it wasn’t authenticated. In your account settings, make sure ‘my outgoing server requires authentication’ is enabled and set to use the same username and password as your incoming mail. Once authentication is on, the 530 error clears.
Does BTinternet email still work if I’ve left BT broadband?
It depends what you did when you left. For 60 days after leaving BT Broadband you can move your mailbox to BT’s paid Premium Mail, or link it to another BT Broadband line for free — either of which keeps it working in Outlook. If you did neither, the mailbox drops to free Basic email, which only works through BT webmail in a browser and can’t send or receive through Outlook at all. In that case no settings change will help; you’d need Premium Mail or a linked BT line to use it in an email app again.
Should I use port 465 or port 587?
Either can work — the key is matching the encryption. Port 465 needs SSL; port 587 needs STARTTLS. Start with 465 and SSL, as that’s BT’s published setting. If that won’t send, re-add the account using 587 with STARTTLS (new Outlook won’t let you swap the port on an existing account). Never mix them — 465 with STARTTLS, or 587 with SSL — as that fails silently.
Can you just set this up for me?
Absolutely — this is a common job for us. We connect remotely, check your BT settings, get sending working while you watch, and make sure your other devices still match. It’s no fix, no fee, so if we can’t get your BTinternet email sending, you don’t pay. Call 01202 775566 or text 07520 615332.
Will switching to Classic Outlook fix it?
Often, yes. Several BT users can send in Classic Outlook but not in new Outlook, because Classic gives full manual control of the SMTP port and encryption. It’s a fair short-term workaround while Microsoft matures new Outlook’s IMAP support. See our guide on going back to Classic Outlook for the toggle.
Is there anything a settings change can’t fix?
Yes. If sending fails in BT’s own webmail as well as in Outlook, the problem is your mailbox or BT account — not the settings — and only BT can restore it. The same applies if your BT ID is locked or the mailbox has been closed. We’ll always tell you honestly when it’s a BT-side issue rather than something we can fix.
BTinternet still won’t send?
We’ll connect remotely, fix your outgoing server settings and get your BT email sending — usually the same day. No fix, no fee.
01202 775566 · help@365techies.co.uk · MON–FRI 9AM–5PM