If your emails are bouncing, landing in spam folders, or getting flagged with an "SPF fail" error — even though you're sending from your own company email address — the most common cause is a misconfigured outgoing mail server (SMTP) setting in Microsoft Outlook.
The fix takes under five minutes and does not require any DNS changes, technical expertise, or help from your hosting provider. Here is exactly what is happening and how to fix it.
Why This Happens
When you send an email, Outlook needs to authenticate — log in with your username and password — before handing the message off to be delivered. This proves to mail servers around the world that you are genuinely you, and not someone pretending to send mail on your behalf.
Older or incorrectly configured Outlook profiles sometimes skip this step. Instead of logging in properly, Outlook connects directly using your home or office internet connection's IP address, with no login at all.
The problem: that IP address is not on the approved list of senders for your domain (called an SPF record). So when the receiving mail server checks "is this really allowed to send as this address?", the answer is no — and your email gets flagged, rejected, or buried in spam, even though it really did come from you.
This is especially common on older Outlook installations (2007, 2010, 2013) where settings were configured years ago and never updated, or where settings were copied from an old computer.
How to Check and Fix It
- Open Outlook.
- Click File → Account Settings → Account Settings...
- Select your email account from the list and click Change...
- Click More Settings...
- Go to the Outgoing Server tab.
- Make sure "My outgoing server (SMTP) requires authentication" is ticked.
- Select "Use same settings as my incoming mail server" — this is correct for almost all setups.
- Go to the Advanced tab.
- Check the Outgoing server (SMTP) port number:
- It should be 587 (with TLS / STARTTLS encryption), or 465 (with SSL encryption) — not 25.
- If it shows port 25, change it to 587 and set the encryption type to TLS (sometimes labelled STARTTLS).
- Click OK, then Next, then Finish.
- Send yourself a test email to confirm everything still works.
What If I Don't Know My Correct Settings?
If you are not sure what port or encryption type to use, contact your hosting provider or IT support. For EDZNET clients, reach out to support and we will confirm the correct outgoing server settings for your specific mailbox.
Still Having Issues?
If you have confirmed authentication is enabled and the port is correct but you are still seeing delivery problems, check:
- Whether your account password has expired or recently changed (and Outlook is using a saved old password)
- Whether your internet provider blocks port 25 or 587 outbound — some ISPs do this to reduce spam. Switching networks (e.g. trying on mobile data) can help confirm this
- Whether the issue is specific to one device or affects all your devices and apps
If none of that resolves it, contact support with the exact error message you are seeing and we can dig into the server-side logs for you.
Frequently Asked Questions
Why does this matter if the email is "really" from me?
Mail servers cannot take your word for it — anyone could put your name in the "From" field. Authentication is how your email provider proves to the rest of the internet that the message genuinely came from your account, not someone impersonating you.
Will this fix happen automatically?
No — this is a one-time setting in your email client and needs to be corrected manually per device or account.
I use webmail, not Outlook — does this affect me?
No. Webmail (browser-based email) always authenticates properly by design. This issue is specific to desktop and mobile email clients with outdated or incorrect server settings.
Do I need to change my SPF record?
Probably not. In most cases the SPF record is already configured correctly by your hosting provider — the problem is simply that Outlook is not authenticating before sending. Fixing the Outlook setting resolves the SPF failure without any DNS changes.
Does this affect iPhone / Android email apps too?
Yes — the same principle applies to any email client that sends via SMTP. If you see the same SPF fail errors on your phone's mail app, check that outgoing server authentication is enabled there too.
