# Email Security: SPF, DKIM, DMARC, Quarantine | SmartMail > Each incoming email is checked by SPF, DKIM and DMARC; results and reasons are logged. Mail below the trust threshold is quarantined and all actions are logged. Source page: https://dblinx.net/en/smartmail/guvenlik --- Email security # Email security: every email is measured, its rationale is recorded Email below the trust threshold is quarantined; every action is logged. [Buy ](https://app.dblinx.net/satin-al?urun=smartmail)[Try the demo](https://mail.dblinx.net/demo/) Quarantine Authentication ## SmartMail calculates SPF, DKIM and DMARC itself A result written by another server that the email passed through in transit cannot be trusted. - PTR record and forward validation - The domain's DNS records are queried directly - The result is always visible, independent of AI Phishing ## Impersonation is caught by following the address trail Similar domain, display name, reply address, and link are measured separately. - the difference between ornek-lojistlk and ornek-lojistik is highlighted - An email whose display name says the organization and whose address says someone else - A link whose text differs from its destination is considered misleading Quarantine ## Emails below the threshold do not land in the mailbox It is not deleted; it remains in a separate folder together with its reason. - A user with quarantine permission releases it - Permanent decision for sender or domain name - Corrections are included in the next evaluation Threshold ## See the result before changing the threshold Emails affected by the new threshold are listed before saving. - The company administrator sets the threshold - If desired, it is also applied to existing emails in the mailbox - The administrator's explicit rules come before every prediction Administration · Settings Privacy ## When the email is opened, the sender does not learn this Remote images are blocked by default; displaying them is the user's decision. - The body is displayed in an isolated frame - Cannot access the hidden script panel - Misleading link is also flagged ## Beyond incoming email ### Integrity document Every email is archived with its SHA-256 hash; at that moment, it is re-verified as unchanged. ### Send securely Content and attachments do not go to the recipient's mailbox; only a link valid for 1-30 days is sent. ### IBAN change Fraudulent supplier indicators are assessed together and flagged with a warning reason. [ ### Audit log Every action with person, time and IP; automatic quarantine as “System”. ](yonetim.html) ### Company-level isolation Each company's data resides in its own isolated space and is not visible to anyone else. ### Same reason on mobile The risky badge and warnings are visible on the phone with the same justification. How to do it ## Step by step ### Reviewing and releasing a quarantined email - Open the Quarantine folder on the left and click the email you want to review. The quarantine reason appears above the email; for details, click the badge next to the sender name. - If the email is trustworthy, click 'Release from Quarantine'. [The entire document ](/en/smartmail/belgeler/kullanici/karantinadaki-maili-inceleme) ### Setting the quarantine confidence threshold - Open Settings from the left-hand menu and go to the Quarantine trust threshold row. - Drag the slider or enter a percentage in the box next to it. The higher the threshold, the more emails are quarantined. - Read the preview appearing at the bottom. The line "With this threshold... emails are quarantined" and example email subjects show the impact of the threshold on emails in the inbox. - Save the threshold with Save in the row. The saved threshold affects emails received from then on. - If you also want to apply the threshold to emails already in the inbox, click Apply to existing emails and select Yes, apply in the confirmation that opens. [The entire document ](/en/smartmail/belgeler/yonetici/karantina-esigini-ayarlama) Guides ## Read the subject in depth [ ### What is email quarantine, why does a suspicious email end up in quarantine? Email quarantine is the holding of an email deemed suspicious in a separate area before it reaches the inbox ](/en/smartmail/rehberler/eposta-karantinasi-nedir) ## FAQs How does SmartMail detect phishing emails? The sender is verified with SPF, DKIM, DMARC, and PTR records; similar domain names, impersonation with international characters, display name and brand impersonation, reply address, and link inconsistencies are measured separately. The entire text is evaluated by AI and the result is written with justification. Is a quarantined email deleted? The quarantined email is preserved: it stays in a separate folder together with the reason for quarantine and can be released by a user with quarantine permission. These corrections are saved and taken into account in subsequent evaluations. Can the quarantine threshold be changed? Yes. The company administrator sets the threshold. Which emails the new threshold will affect is listed before saving, and if desired it is also applied to existing emails in the mailbox. [All questions ](sss.html) Continue ## Other sides of SmartMail [ ### Shared mailboxes Manage shared mailboxes as a team ](paylasimli-kutu.html)[ ### Send control Approval for mail sent on behalf of the organization ](gonderim-denetimi.html)[ ### AI Summary, attachment analysis, classification ](yapay-zeka.html)[ ### Team collaboration Internal note, mention, conversation thread ](ekip-calismasi.html)[ ### Administration Mailboxes, nine permissions, audit log ](yonetim.html)[ ### Documents Every task step by step, with screenshots. ](/en/smartmail/belgeler/) ## Let's plan SmartMail for your organization Select the number of mailboxes and start now. Migration and analysis of your old emails are free during the initial setup. [Buy ](https://app.dblinx.net/satin-al?urun=smartmail)[Try the demo](https://mail.dblinx.net/demo/) - Nine permissions per mailbox - Reasoned analysis in every email - Same rules on web and mobile