Is your email down and your client is waiting for an important offer? Few things can cause as much stress in a company as an email outage. Suddenly, you lose contact with clients, suppliers, and co-workers. Important messages don't get through, and you don't know if anyone is trying to contact you. This situation can cost your company lost orders, customer trust, and even money.
In this article, we will present the most common causes of problems with business email and suggest how to solve them. We will also show you when it is worth stopping trying to fix it yourself and contacting specialists so as not to waste valuable time.
Contents
- Common causes of company email not working
• DNS Error - Bad or Missing MX Records
• Mailbox full
• IP address of the server on the blacklist (blacklist)
• Authentication error / bad password
• No connection to mail server - What You Can Do Yourself – A Quick Checklist
- When is it worth calling a specialist?
- How can we help?
Common causes of company email not working
🔁DNS Error - Bad or Missing MX Records
What are MX records and why are they so important?
MX (Mail Exchange) records are special entries in the DNS (Domain Name System) that indicate where mail sent to addresses in your domain should go. In simpler terms, they are road signs that say: "If someone sends email to jan@yourcompany.pl, then the message should go to that specific mail server."
What happens when MX records are set incorrectly?
If MX records are incorrect or missing, emails may:
- • Not reach at all
- • Return to sender with error message
- • Getting to the wrong server
- • Be delayed for many hours or days
How to check MX records?
You can easily check your domain's MX records using an online tool such as: MXToolbox. Just enter your domain name (e.g. yourcompany.pl) and click "MX Lookup". Correct records should point to your email service provider's servers.
📥Mailbox full
When does this happen?
The problem is especially true for older IMAP email accounts, where storage limits are relatively small (often 1-5 GB). If you don't clean your mailbox regularly or store large attachments, storage can quickly run out.
Symptoms of an overflowing mailbox:
- • No new messages are coming in
- • Senders receive a delivery error message
- • You see a message about insufficient space when trying to send or receive a message
- • You cannot save draft messages
How to check and solve it?
- Check the level of your mailbox – log in to webmail (browser-based email) or check the administration panel of your email provider.
- Solutions:
- • Delete unnecessary messages (especially those with large attachments)
- • Archive older messages to local disk
- • Ask your administrator to increase your storage limit
- • Consider moving to a more modern email solution with higher limits
🚫Server IP address on blacklist
What is a blacklist?
Blacklists are special databases containing IP addresses of servers that have been identified as sources of spam or other unwanted activity. Organizations such as Spamhaus, SORBS, and Barracuda maintain such lists, and many mail servers check them before accepting messages.
Symptoms of a blacklist problem:
- • Sent messages come back with an error message
- • Emails end up in recipients' spam folders
- • Some recipients (e.g. from specific companies) do not receive your messages
- • The problems only concern outgoing mail, incoming mail works normally
How to check if your server is blacklisted?
Use the tool MXToolbox Blacklist Check and enter the IP address of your mail server (you can find it in your mail settings or ask your administrator) – https://mxtoolbox.com/ - MXtoolbox website
What to do if a server is blacklisted?
- Short term: You can submit a request to be removed from a blacklist (delisting) on the website of the operator of the given list.
- Long term: Implement proper security configuration:
- • SPF (Sender Policy Framework) – determines which servers can send mail on behalf of your domain
- • DKIM (DomainKeys Identified Mail) – adds a digital signature to the message
- • DMARC (Domain-based Message Authentication, Reporting & Conformance) – specifies what to do with messages that fail SPF/DKIM verification
🛑Authentication error/bad password
Common causes of authentication problems:
- • Recent password change that has not been updated in the email client
- • Account lockout after multiple failed login attempts
- • Password expiration (some companies have passwords expiring every 30-90 days)
- • Incorrect configuration in the email program (e.g. Outlook)
- • SSL/TLS certificate issues
Where to look for error information:
- • Error messages in the email program (e.g. Outlook)
- • Webmail Logs
- • Email notifications for failed login attempts
- • Mail administration panel
How to solve the problem:
- Check if you can log in via webmail (browser mail)
- Reset your password if necessary
- Make sure you have the latest details entered in your email program
- Delete and re-add the account in your email program
- Check if the server requires special SSL/TLS settings
No connection to mail server
Possible causes:
- • Local internet connection issues
- • Failure at the postal service provider
- • Blocking ports by firewall (most often ports 25, 465, 587, 993, 995)
- • Changing mail server addresses (e.g. after migration)
- • Problems with SSL/TLS certificates
How to diagnose the problem:
- Check if you have access to other websites
- Try connecting to the mail server from another device or network
- Check if the mail server is running (you can use online tools to check the status)
- Contact other users of the same email to confirm if the problem is specific to you
What You Can Do Yourself – A Quick Checklist
Before you call for help, try these simple steps:
Check your internet connection
- • Can you browse other websites?
- • Try opening a few different websites to make sure the internet is working properly.
Log in via webmail
- • Try accessing your email via a browser (webmail)
- • If webmail works but your email program does not, the problem is probably in the program's configuration.
Check DNS records and blacklists
- • Use MXToolbox(link above) to check your MX records and see if your server is blacklisted.
Check the level of your mailbox
- • Log in to your admin panel or webmail to check how much space you have left.
If you use Outlook:
- • Restart the program
- • Check if Outlook is in offline mode ("Send/Receive" tab > "Work Offline" should not be checked)
- • Refresh credentials (File > Info > Account Settings > select account > Change > re-enter password)
- • Run the repair tool (File > Info > Account Tools > Repair)
Check on another device
- • If you have access to another computer or phone, check whether the problem occurs there as well.
When is it worth calling a specialist?
Solving problems on your own is good, but sometimes it's better to play it safe and get help from professionals. Here are some situations where you should consider contacting an IT specialist:
When the mail is down for more than 30 minutes
- • Time is money, especially in business. If the problem persists, it may indicate a more serious failure.
When customers report that their messages are bouncing
- • This may indicate problems with DNS records, blacklists or a full mailbox.
When you don't know how to access the DNS or server administration panel
- • Some repairs require access to advanced settings, which, if modified without the proper knowledge, may worsen the situation.
When you are afraid of losing your message
- • Improper repair attempts can sometimes lead to data loss.
When the problem affects the entire company, not just a single user
- • This may indicate a systemic problem that requires professional intervention.
How can we help – Simple IT
At Proste IT, we specialize in quickly solving problems with corporate email. Our experience allows us to effectively diagnose and repair even the most complex failures.Our corporate mail services:
Quick diagnosis and repair
- • Quick identification of the cause of the problem
- • Fixing DNS errors, MX records, SSL certificates
- • Configuration of forwarding and email aliases
- • Unlocking accounts and resetting passwords
Email Security Audit
- • Checking for susceptibility to phishing attacks
- • Verification of anti-spam protection
- • Log analysis for unauthorized access attempts
- • Recommendations for improving safety
Implementation of correct security configuration
- • Configuring SPF, DKIM and DMARC records
- • SSL/TLS encryption setting
- • Implementing multi-factor authentication (MFA)
- • Protection against data leakage
Constant IT support
- • Regular monitoring of email activity
- • Proactively resolve issues before they impact your work
- • Quick response to reports
- • Consulting on the optimization of postal services
- While you can solve some of these problems yourself, in many cases it will be faster and safer to seek help from a specialist. Remember that every minute without working email can cost your company lost business opportunities.
📞 Need a quick Help?
Contact us – we will solve the problem today! Our specialists are available to restore your business email in the shortest time possible – https://prosteit.pl/kontakt/
Simple IT – we make technology work for you, not against you.
English 
Polski