Added FAQ

FAQ.md

@@ -153,6 +153,7 @@ FairEmail follows all the best practices for an email client as decribed in [thi
 * [(89) How can I send plain text only messages?](#user-content-faq89)
 * [(90) Why are some texts linked while not being a link?](#user-content-faq90)
 * [(91) Can you add periodical synchronization to save battery power?](#user-content-faq91)
+* [(92) Can you add verification of the DKIM signature and SPF authorization?](#user-content-faq92)
 
 [I have another question.](#support)
 
@@ -1485,6 +1486,14 @@ so periodically synchronizing messages will not result in saving battery power,
 
 <br />
 
+<a name="faq92"></a>
+**(92) Can you add verification of the DKIM signature and SPF authorization?**
+
+Verification of the [DKIM](https://en.wikipedia.org/wiki/DomainKeys_Identified_Mail) signature
+and [SPF](https://en.wikipedia.org/wiki/Sender_Policy_Framework) authorization is a task of email servers, not of an email client.
+
+<br />
+
 
 ## Support