Email problems?
Emails going to spam, not arriving at all, or SPF/DKIM/DMARC errors? We diagnose and fix your email problems fast and correctly.
The most common email problems and how to solve them
Email problems hit at the worst time - right when you need to reply to a customer, send an invoice or confirm a meeting. The most common email issues we troubleshoot are: emails not arriving (delivery problems), emails landing in spam, blocked email from Microsoft 365 or Gmail, Outlook errors, SMTP/IMAP authentication failures and broken contact forms. Below we walk through each one with concrete fixes.
Email goes to spam
Your emails land in the recipient spam folder. Almost always missing or incorrect SPF, DKIM or DMARC records.
Mail not arriving
Sent emails never reach the recipient. Caused by DNS errors, blacklisting or server configuration issues.
SPF / DKIM / DMARC
Authentication records missing or misconfigured. We set up and validate all three for maximum deliverability.
Cannot send or receive
Mail client errors, SMTP/IMAP configuration problems or full mailbox. We diagnose and resolve fast.
Microsoft 365 mail blocks you
Your mail is blocked by Microsoft 365 or Gmail. Reputation problem or blacklisted IP - we fix it.
Contact form does not send
Form mail blocked by hosting or marked as spam. We solve it with our WF SMTP service.
Mail not arriving - how to troubleshoot delivery problems
When a customer says "I never got your email", every minute matters. Email delivery problems can come from your sending side, the recipient side or the network in between. The good news is that 90 percent of delivery problems can be diagnosed in five steps. Work through them in order.
- Step 1: Check your "Sent" folder. If the email is not in Sent, it never left your client. Check Outbox for stuck items and SMTP errors.
- Step 2: Look at the email headers. Ask the recipient to forward the bounce or check spam. Headers reveal exactly which mail server rejected the message and why.
- Step 3: Verify MX-record for the recipient domain. Run
dig MX recipient-domain.comor use mxtoolbox.com. A missing MX-record means no server is accepting mail for that domain. - Step 4: Test from another sender domain. If your Gmail/personal email gets through but your business email does not, the email problem is on your sending domain (SPF/DKIM/DMARC, blacklist, reputation).
- Step 5: Check blacklists and reputation. Run mxtoolbox blacklist check on your sending IP and domain. Spamhaus, Spamcop and Barracuda are the major lists.
If the email is "delivered" according to your headers but the recipient says it never arrived, it has likely landed in their spam folder, junk folder or quarantine. Ask the recipient to check there first - this resolves a large fraction of "missing email" cases without any technical work.
SPF, DKIM and DMARC explained simply
These three records together prevent email problems caused by spoofing and decide whether your mail goes to inbox or spam. They are mandatory for anyone sending business email in 2026 - especially after Microsoft 365 mail and Gmail tightened their requirements.
SPF (Sender Policy Framework)
A TXT record that lists the servers allowed to send email from your domain. Receivers reject or spam-folder mail from servers not listed.
Example record:
v=spf1 include:spf.protection.outlook.com include:_spf.webbfabriken.com -allDKIM (DomainKeys Identified Mail)
A cryptographic signature added to each outgoing email. Recipients use the matching public key (in DNS) to verify the message was not altered in transit.
Example record:
selector1._domainkey.example.com TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3..."DMARC (Domain-based Message Authentication, Reporting and Conformance)
A TXT record that tells receiving servers what to do if SPF or DKIM fail (none, quarantine, reject) and where to send aggregate reports. DMARC is the policy layer that ties SPF and DKIM together.
Example record:
_dmarc.example.com TXT "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.com; pct=100"When Microsoft 365 or Gmail blocks your emails
Microsoft 365 mail and Gmail together cover about 80 percent of business inboxes. When they start rejecting your emails, customer communication grinds to a halt. The reasons are almost always: poor sender reputation, IP on a blacklist, or failing SPF/DKIM/DMARC. Here is how to fix it.
Diagnosis steps
- Read the bounce message. Microsoft and Google return specific error codes - "550 5.7.1", "421 4.7.0" etc. Each code points to a specific rejection reason.
- Check IP blacklists. Run mxtoolbox blacklist check on your sending IP. Spamhaus is the most influential.
- Check Microsoft SNDS. Smart Network Data Services shows your reputation toward Microsoft 365 mail and Hotmail/Outlook.com.
- Check Google Postmaster Tools. Domain reputation, IP reputation, spam rate and authentication status toward Gmail.
- Validate SPF, DKIM and DMARC. Use mail-tester.com to score your messages 0-10. Anything below 8 is an email problem in itself.
How to recover sender reputation
- Request delisting from Spamhaus, Microsoft and Google.
- Fix all SPF, DKIM and DMARC records to perfect alignment.
- Reduce sending volume temporarily and warm up gradually.
- Remove inactive subscribers and bounce-prone addresses.
- Add an unsubscribe link in every marketing email.
Outlook not working - common error messages
Outlook is the email client we troubleshoot most often. The same handful of errors come up again and again - here is what they mean and how to fix them.
"Cannot connect to mail server"
Outlook cannot reach the IMAP/SMTP server. Check internet connection, firewall (port 993, 587 must be open), incoming/outgoing server addresses and SSL/TLS settings. Antivirus software often blocks Outlook ports.
"Autodiscover failed"
Outlook cannot find autodiscover.example.com or _autodiscover._tcp.example.com. The DNS record is missing or wrong. We add a CNAME pointing to autodiscover.outlook.com for Microsoft 365 mail customers.
"Authentication required"
SMTP server requires authentication but Outlook is configured without it. Open Account Settings, Outgoing Server, check "My outgoing server requires authentication". For Microsoft 365 mail, modern authentication (OAuth2) must be enabled.
"0x800CCC0E" / "0x80042108"
Generic Outlook connection errors. Almost always firewall, antivirus, wrong port, or expired password. We work through the standard checklist - in 95 percent of cases the email problem is identified within minutes.
"Need password" loop
Outlook keeps prompting for password. Cause: corrupted credential cache. Open Credential Manager, remove all Microsoft Office and Outlook entries, restart Outlook and re-enter credentials.
"OST file is corrupted"
The local Outlook data file is corrupted. Close Outlook, navigate to %localappdata%\Microsoft\Outlook, rename the .ost file to .ost.bak. Outlook rebuilds it automatically on next start.
IMAP vs POP3 - which one should you use?
A surprising number of email problems we troubleshoot start with the wrong protocol choice. POP3 is a 1980s design where emails are downloaded to one device and then often deleted from the server. IMAP is a 1990s design where emails stay on the server and synchronize across all devices.
Use IMAP if...
- You read mail on more than one device (computer + phone).
- You want webmail to show the same content as the desktop client.
- You want server-side backup of mail history.
- You use Microsoft 365 mail or Google Workspace.
Use POP3 only if...
- You have very limited mailbox quota and need local storage.
- You read mail on exactly one device, never another.
- You have a specific compliance reason to keep mail off the server.
For 99 percent of business cases the answer is IMAP. We help migrate from POP3 to IMAP without losing email - including pulling messages stored only on a single old laptop.
Webbfabriken email support - what is included
We deliver email solutions and email-problem support across three layers: the email service itself, the SMTP delivery service for websites, and configuration help. Below is what is included in each.
Microsoft 365 package
Full Microsoft 365 mail with Exchange Online, Teams, OneDrive, SharePoint and Office apps. We migrate from your current provider, set up SPF/DKIM/DMARC, configure Outlook on all devices and provide ongoing Swedish support.
- Per-user licensing in Swedish kronor
- Migration without downtime
- DNS configuration and validation
- Outlook setup, mobile setup
WF SMTP (authenticated SMTP for websites)
Our own SMTP relay specifically for sending email from contact forms, e-commerce platforms and CRM systems. Solves the most common contact-form email problem - that PHP mail() does not authenticate and gets blocked or marked as spam.
- Authenticated SMTP with proper SPF/DKIM
- Form-mail and transactional email
- Logs and delivery reports
- WordPress, Magento, custom CMS support
Email problem support
On-demand troubleshooting for any email issue. We diagnose, fix and document. Available as a one-off engagement or part of an ongoing IT support agreement.
- SPF, DKIM, DMARC setup and audit
- Blacklist removal
- Outlook, Apple Mail, Thunderbird configuration
- Migration between mail providers
Diagnosis
We analyze your DNS records, mail headers and server configuration to identify the exact email-problem cause.
Configuration
We configure SPF, DKIM and DMARC correctly, update DNS and fix server settings.
Verification
We verify all records propagate correctly and test email delivery to Microsoft 365 mail, Gmail and other major providers.
Email problems - frequently asked questions
Why does my email go to spam?
Email problems with spam-folder placement are usually caused by missing or incorrect SPF, DKIM and DMARC records on your domain. Major providers like Microsoft 365 and Gmail require all three to trust your sender domain. We configure all three records and validate them.
What is the difference between SPF, DKIM and DMARC?
SPF (Sender Policy Framework) lists which servers may send email from your domain. DKIM (DomainKeys Identified Mail) cryptographically signs each message so recipients can verify it was not altered. DMARC tells receiving servers what to do if SPF or DKIM fail. All three together provide modern email authentication and prevent spoofing.
Why is Microsoft 365 blocking my emails?
Microsoft 365 blocks email when sender reputation is low, when SPF/DKIM/DMARC validation fails, or when the sending IP is on a blacklist. We check Microsoft SNDS, fix authentication records and request delisting where needed.
Should I use IMAP or POP3?
For business use IMAP is the right answer. IMAP keeps email on the server and synchronizes across all devices (Outlook, mobile, webmail). POP3 downloads and removes email from the server, so messages only exist on one device. POP3 is legacy and we generally recommend migrating from POP3 to IMAP.
My contact form does not send email - why?
Most contact form email delivery issues come from PHP mail() being unauthenticated, blocked by hosting providers, or marked as spam. The fix is to use authenticated SMTP. We have built our own WF SMTP service for exactly this and configure it for hundreds of customer websites.
Can you help us migrate to Microsoft 365?
Yes. We migrate email from any provider (old IMAP, Google Workspace, on-premise Exchange) to Microsoft 365 with full mailbox content, calendar, contacts and DNS configuration. Migration runs without downtime for end users.
Need help with email?
Contact us and we'll diagnose your email problem. Swedish IT support since 2002.
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