diff --git a/app/dashboard/templates/dashboard/custom_alias.html b/app/dashboard/templates/dashboard/custom_alias.html
index f6113416..9927d23e 100644
--- a/app/dashboard/templates/dashboard/custom_alias.html
+++ b/app/dashboard/templates/dashboard/custom_alias.html
@@ -43,12 +43,22 @@
 
           <div class="col-sm-6 p-1">
             <select class="form-control" name="suffix">
-              {% for suffix in suffixes %}
-                <option value="{{ suffix[2] }}">
-                  {% if suffix[0] %}
-                    {{ suffix[1] }} (your domain)
+              {% for suffix_info in suffixes %}
+                <option value="{{ suffix_info.signed_suffix }}"
+                    {% if suffix_info.is_premium %}
+                      title="Only available to Premium accounts"
+                    {% elif not suffix_info.is_custom and at_least_a_premium_domain %}
+                      title="Available to all accounts"
+                    {% endif %}
+                >
+                  {% if suffix_info.is_custom %}
+                    {{ suffix_info.suffix }} (your domain)
                   {% else %}
-                    {{ suffix[1] }}
+                    {% if suffix_info.is_premium %}
+                      {{ suffix_info.suffix }} (Premium domain)
+                    {% else %}
+                      {{ suffix_info.suffix }} (Public domain)
+                    {% endif %}
                   {% endif %}
                 </option>
               {% endfor %}
diff --git a/app/dashboard/views/custom_alias.py b/app/dashboard/views/custom_alias.py
index 5b0b053c..5614bf0d 100644
--- a/app/dashboard/views/custom_alias.py
+++ b/app/dashboard/views/custom_alias.py
@@ -1,3 +1,5 @@
+from dataclasses import dataclass
+
 from flask import render_template, redirect, url_for, flash, request
 from flask_login import login_required, current_user
 from itsdangerous import TimestampSigner, SignatureExpired
@@ -47,6 +49,50 @@ def available_suffixes(user: User) -> [bool, str, str]:
     return suffixes
 
 
+@dataclass
+class SuffixInfo:
+    is_custom: bool
+    suffix: str
+    signed_suffix: str
+    is_premium: bool
+
+
+def available_suffixes_more_info(user: User) -> [SuffixInfo]:
+    """
+    Similar to as available_suffixes() but also return whether the suffix comes from a premium domain
+    Note that is-premium-domain is only relevant for SL domain
+    """
+    user_custom_domains = user.verified_custom_domains()
+
+    suffixes: [SuffixInfo] = []
+
+    # put custom domain first
+    # for each user domain, generate both the domain and a random suffix version
+    for alias_domain in user_custom_domains:
+        suffix = "@" + alias_domain.domain
+        suffixes.append(SuffixInfo(True, suffix, signer.sign(suffix).decode(), False))
+        if alias_domain.random_prefix_generation:
+            suffix = "." + random_word() + "@" + alias_domain.domain
+            suffixes.append(
+                SuffixInfo(True, suffix, signer.sign(suffix).decode(), False)
+            )
+
+    # then SimpleLogin domain
+    for sl_domain in user.get_sl_domains():
+        suffix = (
+            ("" if DISABLE_ALIAS_SUFFIX else "." + random_word())
+            + "@"
+            + sl_domain.domain
+        )
+        suffixes.append(
+            SuffixInfo(
+                False, suffix, signer.sign(suffix).decode(), sl_domain.premium_only
+            )
+        )
+
+    return suffixes
+
+
 @dashboard_bp.route("/custom_alias", methods=["GET", "POST"])
 @login_required
 def custom_alias():
@@ -60,8 +106,12 @@ def custom_alias():
         return redirect(url_for("dashboard.index"))
 
     user_custom_domains = [cd.domain for cd in current_user.verified_custom_domains()]
-    # List of (is_custom_domain, alias-suffix, time-signed alias-suffix)
-    suffixes = available_suffixes(current_user)
+    suffixes = available_suffixes_more_info(current_user)
+    at_least_a_premium_domain = False
+    for suffix in suffixes:
+        if not suffix.is_custom and suffix.is_premium:
+            at_least_a_premium_domain = True
+            break
 
     mailboxes = current_user.mailboxes()
 
@@ -180,6 +230,7 @@ def custom_alias():
         "dashboard/custom_alias.html",
         user_custom_domains=user_custom_domains,
         suffixes=suffixes,
+        at_least_a_premium_domain=at_least_a_premium_domain,
         mailboxes=mailboxes,
     )
 
diff --git a/app/models.py b/app/models.py
index 263edda0..982dd533 100644
--- a/app/models.py
+++ b/app/models.py
@@ -560,14 +560,15 @@ class User(db.Model, ModelMixin, UserMixin):
         - SimpleLogin public domains, available for all users (ALIAS_DOMAIN)
         - SimpleLogin premium domains, only available for Premium accounts (PREMIUM_ALIAS_DOMAIN)
         """
+        return [sl_domain.domain for sl_domain in self.get_sl_domains()]
+
+    def get_sl_domains(self) -> ["SLDomain"]:
         if self.is_premium():
-            query = SLDomain.query.all()
+            query = SLDomain.query
         else:
             query = SLDomain.filter_by(premium_only=False)
 
-        domains = [sl_domain.domain for sl_domain in query]
-
-        return domains
+        return query.all()
 
     def available_alias_domains(self) -> [str]:
         """return all domains that user can use when creating a new alias, including: