Spam filter and phishing protection for businessesDanger stays out. Confidential stays in.
MailGuard checks every inbound email for phishing, spam and malware and every outbound one for confidential data. In front of Microsoft 365, Exchange and Conbool Mail.
No credit card required · Cancel anytime
Overview
What MailGuard stops.
Phishing protection, spam filter and malware defence in one. Inbound, outbound and after delivery, one click per topic.
Inbound
Phishing caught before anyone clicks.
MailGuard checks senders, links and QR codes. Every link is checked again at click time.
- SPF, DKIM, DMARC and ARC
- Fake sign-in pages
- QR codes in images and PDFs
Inbound
Fake bosses stand out.
When someone poses as management or accounting, MailGuard flags it. Even with domains that only look similar.
- Forged display names
- Lookalike domains, including Cyrillic
- Urgent payment requests
Inbound
Attachments are defused.
Archives are unpacked, the real file type detected, macros and active content removed. That keeps malware out.
- Real file type, not the extension
- Macros and PDF scripts removed
- Encrypted archives detected
Inbound
Spam gone, what matters stays.
All findings add up to a score. Your threshold decides: deliver, tag or quarantine.
- rspamd, Spamhaus, our own AI model
- New spam waves caught within minutes
- Daily digest for every user
Outbound
Typo? MailGuard notices.
When an unknown domain matches a known one except for a single letter, MailGuard flags it.
- customer-gmhb.com instead of customer-gmbh.com
- Reported by default
- Blocked if you want
OutboundDLP · add-on
Confidential stays in house.
DLP finds sensitive data in text, attachments and images. You decide what happens next.
- IBAN, credit cards, health data
- Text recognition in images and scans
- Block, approve, encrypt
After delivery
Delivered mail is checked again.
Every six hours MailGuard re-checks the mail of the last 72 hours. Findings can be pulled out of mailboxes automatically.
- Links re-checked at click time
- Instant alert to your IT
- Removed automatically if you want
For your IT
Every decision can be traced.
Each email shows what was found and why. You set the thresholds.
- Quarantine with one-click releaseYour IT releases or deletes. Employees release harmless mail from the daily digest.
- Report right in OutlookReport something suspicious or choose "Not junk". Your IT sees it at once.
- Rules per groupStricter for management and accounting, exceptions for newsletters, lists per person or domain.
- Directory and SIEM integrationEntra ID, Active Directory, LDAP. Events to Splunk, Sentinel, QRadar or Elastic.
Setup
MailGuard sits in front of your mailbox.
Your mailboxes stay where they are. MailGuard checks in between, in both directions.
- Step 1Add your domainYou verify your domain in the Conbool portal.
- Step 2Connect Microsoft 365The wizard creates the connectors for you.
- Step 3Switch the MX recordFrom then on every email runs through MailGuard. Nothing is delivered unchecked.
Frequently asked questions about Conbool MailGuard
Why isn't the Microsoft 365 spam filter enough?
MailGuard checks before the email reaches Microsoft and covers three gaps: targeted phishing, CEO fraud and attachments whose executable parts must be removed. No filter can guarantee detection. Microsoft 365 remains your mailbox, MailGuard only sits in front of it.
How does MailGuard protect against links that turn malicious later?
Links are rewritten and checked against fresh block lists at click time. In addition, MailGuard re-checks delivered mail of the last 72 hours every six hours. An expired link only shows its target as text and asks for a deliberate click.
Can MailGuard stop confidential data from leaving the company?
Yes, with the DLP add-on. It detects IBANs, credit cards, health data or your own keywords, also in attachments and images, and blocks, holds or encrypts with SecureMail. Every approval is logged.
How does our IT keep false positives under control?
Every decision is listed with its points in the message trace. Employees release harmless mail from the daily digest or report it via the Outlook add-in as "Not junk". Rules per sender, domain or group exempt known partners precisely.
Does the check slow down email?
The check runs while the email is being accepted. How long it takes for you is shown in the portal metrics as the median and the 95th percentile. Large attachments with many images or PDF pages take longer to check than plain text.
Can rules be adjusted for individual departments?
Yes. Management or accounting can, for example, have stricter thresholds and attachment rules than an info mailbox. The groups come from your directory, such as Entra ID or Active Directory.
Does MailGuard read QR codes too?
Yes. QR codes in images and PDF attachments are read, and the target is checked like any other link. QR codes in PDF invoices are a popular way to sneak links past filters.
What happens if a check fails?
MailGuard then temporarily refuses the email instead of delivering it unchecked. The sending server tries again shortly afterwards. So no email is lost and none gets through unchecked.
How do I set up MailGuard?
Verify your domain in the portal, connect Microsoft 365, switch the MX record. The wizard creates the connectors in Exchange Online for you. Until the switch, your email keeps flowing as before.
Do employees need new software?
No. Outlook, Apple Mail and mobile mail apps stay as they are. The Outlook add-in for reporting is optional. Warnings appear as a note in the subject line or a banner in the email.
Does MailGuard also run on our own server?
Yes. MailGuard runs in the Conbool cloud or as your own server on site, with the same checks. Interface and policies are the same in both cases.
Does MailGuard protect against ransomware?
Ransomware usually arrives as an attachment or a link. MailGuard removes macros and scripts, detects disguised file types, scans with current virus signatures and checks links at click time. Anything identified as malware only later is caught by the re-check.
Does MailGuard detect phishing without a link or attachment?
Yes. CEO fraud often comes as plain text. MailGuard looks for forged display names, lookalike domains and payment requests under time pressure, and additionally scores the text with its own AI model.
What is the difference between a spam filter and an email gateway?
A spam filter sorts out unwanted advertising. An email gateway like MailGuard sits in front of the mailbox and checks every email in both directions for phishing, malware, fraud and confidential data.
Does MailGuard work with an on-premises Exchange Server?
Yes. MailGuard sits in front of any mail server, whether Microsoft 365, Exchange Server or Conbool Mail. Email for your domain runs through MailGuard first and is then handed on to your server.
How does MailGuard handle newsletters?
MailGuard recognises newsletters and advertising as a class of their own. You decide whether they are delivered, tagged or quarantined.
How quickly does MailGuard detect new spam waves?
When one customer confirms a spam wave, its fingerprint protects all other customers within minutes. It only learns from confirmed verdicts, never from its own score.
Which plan includes MailGuard?
MailGuard is included from Suite 1 and can be tested free for 30 days. DLP is an add-on. The product overview shows what each suite includes.
Related topics
Read more
- Spam filter for businessesThreshold, quarantine and a daily digest for every user.
- Phishing protectionSpot forged senders and sign-in pages before anyone clicks.
- CEO fraud protectionFake bosses and urgent payment requests stand out.
- Email attachment protectionRemove macros, scripts and disguised files from attachments.
- Ransomware protectionStop ransomware at the attachment and the link.
- Secure Microsoft 365Check in front of Microsoft 365 what it does not catch itself.
Ready for the spam filter that checks both ways?
With your own domain, set up in minutes.
No credit card required · 30 days free · Cancel anytime
Conbool Mail
The mailbox to go with it: Conbool Mail.
Every Conbool Mail plan includes built-in protection against malware and spam. MailGuard adds quarantine, click-time link protection and attachment rules.