Extra email check

src/freedombone-app-keyserver

     fi
     if [[ "$other_keyserver_email" != "pgp-public-keys@" ]]; then
         if [[ "$other_keyserver_email" == *"@"* ]]; then
-            keyserver_create_mailsync
-            if ! grep -q "$other_keyserver_email" /etc/sks/mailsync; then
-                echo "$other_keyserver_email" >> /etc/sks/mailsync
-                chown -Rc debian-sks: /etc/sks/mailsync
+            if [[ "$other_keyserver_email" == *"."* ]]; then
+                keyserver_create_mailsync
+                if ! grep -q "$other_keyserver_email" /etc/sks/mailsync; then
+                    echo "$other_keyserver_email" >> /etc/sks/mailsync
+                    chown -Rc debian-sks: /etc/sks/mailsync
+                fi
             fi
         fi
     fi