suggestion

app/dashboard/views/custom_alias.py

@@ -174,35 +174,23 @@ def verify_prefix_suffix(user, alias_prefix, alias_suffix) -> bool:
 
     # make sure alias_suffix is either .random_word@simplelogin.co or @my-domain.com
     alias_suffix = alias_suffix.strip()
-    if alias_suffix.startswith("@"):
-        alias_domain = alias_suffix[1:]
-        # alias_domain can be either custom_domain or if DISABLE_ALIAS_SUFFIX, one of the default ALIAS_DOMAINS
-        if DISABLE_ALIAS_SUFFIX:
-            if (
-                alias_domain not in user_custom_domains
-                and alias_domain not in ALIAS_DOMAINS
-            ):
-                LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
-                return False
-        else:
-            if alias_domain not in user_custom_domains:
-                LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
-                return False
-    else:
-        if not alias_suffix.startswith("."):
+    # alias_domain_prefix is either a .random_word or ""
+    alias_domain_prefix, alias_domain = alias_suffix.split("@", 1)
+
+    # alias_domain must be either one of user custom domains or built-in domains
+    if alias_domain not in user_custom_domains and alias_domain not in ALIAS_DOMAINS:
+        LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
+        return False
+
+    # built-in domain case:
+    # 1) alias_suffix must start with "." and
+    # 2) alias_domain_prefix must come from the word list
+    if alias_domain in ALIAS_DOMAINS and alias_domain not in user_custom_domains:
+        if not alias_domain_prefix.startswith("."):
             LOG.exception("User %s submits a wrong alias suffix %s", user, alias_suffix)
             return False
 
-        full_alias = alias_prefix + alias_suffix
-        if not email_belongs_to_alias_domains(full_alias):
-            LOG.exception(
-                "Alias suffix should end with one of the alias domains %s",
-                user,
-                alias_suffix,
-            )
-            return False
-
-        random_word_part = alias_suffix[1 : alias_suffix.find("@")]
+        random_word_part = alias_domain_prefix[1:]
         if not word_exist(random_word_part):
             LOG.exception(
                 "alias suffix %s needs to start with a random word, user %s",