fix: use protected Date for header when available

Author: link2xt

src/mimeparser.rs

@@ -345,6 +345,18 @@ impl MimeMessage {
                     }
 
                     decrypted_msg = Some(msg);
+
+                    if let Some(protected_timestamp_sent) = decrypted_mail
+                        .headers
+                        .get_header_value(HeaderDef::Date)
+                        .and_then(|v| mailparse::dateparse(&v).ok())
+                    {
+                        timestamp_sent = min(
+                            protected_timestamp_sent,
+                            timestamp_rcvd + constants::TIMESTAMP_SENT_TOLERANCE,
+                        )
+                    }
+
                     if let Some(protected_aheader_value) = decrypted_mail
                         .headers
                         .get_header_value(HeaderDef::Autocrypt)