diff --git a/epdb/admin.py b/epdb/admin.py
index 475053e8..1df5db04 100644
--- a/epdb/admin.py
+++ b/epdb/admin.py
@@ -1,5 +1,8 @@
+import logging
+
 from django.conf import settings as s
 from django.contrib import admin
+from django.contrib import messages
 
 from .models import (
     AdditionalInformation,
@@ -29,6 +32,8 @@ from .models import (
 
 Package = s.GET_PACKAGE_MODEL()
 
+logger = logging.getLogger(__name__)
+
 
 class AdditionalInformationAdmin(admin.ModelAdmin):
     pass
@@ -45,6 +50,113 @@ class UserAdmin(admin.ModelAdmin):
         "date_joined",
     ]
 
+    actions = ["send_welcome_mail", "send_affiliation_mail"]
+
+    @admin.action(description="Send welcome mail")
+    def send_welcome_mail(self, request, queryset):
+        from django.core.mail import EmailMultiAlternatives
+
+        tpl = """Hello {username},
+
+    Your account has been successfully activated.
+
+    To log in, please visit
+    https://envipath.org/password_reset/
+    and request a new password.
+
+    If you have any questions or feedback, feel free to visit our community forum at
+    https://community.envipath.org/.
+    You do not need to register again for the forum - you can log in using your enviPath account by clicking "Log In" and then "Log in with enviPath."
+
+    Best regards,
+
+    The enviPath Team"""
+
+        users = []
+
+        for user in queryset:
+            if user.is_active:
+                logger.info(f"{user.username} already active - not sending mail again")
+                continue
+            try:
+                msg = EmailMultiAlternatives(
+                    "Your enviPath Account Is Now Active",
+                    tpl.format(username=user.username),
+                    "admin@envipath.org",
+                    [user.email],
+                    bcc=["admin@envipath.org"],
+                )
+
+                msg.send(fail_silently=False)
+
+                user.is_active = True
+                user.password = "ASDF"
+                user.save()
+
+                users.append(user)
+                logger.info(f"{user.username} -> {user.email} mail sent")
+            except Exception as e:
+                logger.info(f"Error sending mail to {user.username}: {e}")
+
+        self.message_user(
+            request, f"Sent welcome mail to {[u.email for u in users]}", messages.SUCCESS
+        )
+
+    @admin.action(description="Send affiliation mail")
+    def send_affiliation_mail(self, request, queryset):
+        from django.core.mail import EmailMultiAlternatives
+
+        tpl = """Dear {username},
+
+Thank you for your interest in enviPath!
+
+Please note that the public enviPath system is intended for non-commercial use only.
+We see that you registered using the email address {email}.
+If possible, we kindly ask you to register using an official email address that reflects your affiliation (e.g., a university, NGO, or research organization).
+
+If you would like us to update your account, simply reply to this email and let us know which address we should use.
+We will then change it in our system, and you will receive a password reset email at the new address.
+
+If you are registering with a company email address and are interested in commercial use, you are very welcome to book a meeting with us so we can discuss how we can best support you.
+To book a meeting, please visit https://envipath.com/book
+
+If changing to an affiliation email address is not possible, please contact us at registration@envipath.org
+
+Best regards,
+
+enviPath team"""
+
+        users = []
+
+        for user in queryset:
+            if user.is_active or user.contacted:
+                logger.info(
+                    f"{user.username} already active or already contacted - not sending mail again"
+                )
+                continue
+            try:
+                msg = EmailMultiAlternatives(
+                    "Regarding your enviPath registration",
+                    tpl.format(username=user.username, email=user.email),
+                    "admin@envipath.org",
+                    [user.email],
+                    bcc=["admin@envipath.org"],
+                )
+
+                msg.send(fail_silently=False)
+
+                user.contacted = True
+                user.save()
+
+                users.append(user)
+                logger.info(f"{user.username} -> {user.email} affiliation mail sent")
+            except Exception as e:
+                logger.info(f"Error sending mail to {user.username}: {e}")
+
+        self.message_user(
+            request, f"Sent affiliation mail to {[u.email for u in users]}", messages.SUCCESS
+        )
+
 
 class UserPackagePermissionAdmin(admin.ModelAdmin):
     pass
diff --git a/epdb/migrations/0024_user_contacted.py b/epdb/migrations/0024_user_contacted.py
new file mode 100644
index 00000000..403be979
--- /dev/null
+++ b/epdb/migrations/0024_user_contacted.py
@@ -0,0 +1,17 @@
+# Generated by Django 6.0.3 on 2026-04-21 19:56
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("epdb", "0023_alter_compoundstructure_options_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="user",
+            name="contacted",
+            field=models.BooleanField(blank=True, null=True),
+        ),
+    ]
diff --git a/epdb/models.py b/epdb/models.py
index 67c2c397..311b148c 100644
--- a/epdb/models.py
+++ b/epdb/models.py
@@ -75,6 +75,7 @@ class User(AbstractUser):
         blank=False,
     )
     is_reviewer = models.BooleanField(default=False)
+    contacted = models.BooleanField(null=True, blank=True)
 
     USERNAME_FIELD = "email"
     REQUIRED_FIELDS = ["username"]