portfolio addition email send to admins on registrar invite

src/registrar/templates/emails/portfolio_admin_addition_notification.txt

@@ -0,0 +1,40 @@
+{% autoescape off %}{# In a text file, we don't want to have HTML entities escaped #}
+Hi,{% if portfolio_admin and portfolio_admin.first_name %} {{ portfolio_admin.first_name }}.{% endif %}
+
+An admin was invited to your .gov organization.
+
+ORGANIZATION: {{ portfolio.organization_name }} 
+INVITED BY: {{ requestor_email }}
+INVITED ON: {{date}}
+ADMIN INVITED: {{ invited_email_address }}
+
+----------------------------------------------------------------
+
+NEXT STEPS
+The person who received the invitation will become an admin once they log in to the
+.gov registrar. They'll need to access the registrar using a Login.gov account that's
+associated with the invited email address.
+
+If you need to cancel this invitation or remove the admin, you can do that by going to 
+the Members section for your organization <https://manage.get.gov/>.
+
+
+WHY DID YOU RECEIVE THIS EMAIL? 
+You’re listed as an admin for {{ portfolio.organization_name }}. That means you'll receive a notification
+whenever a new admin is invited to that organization.
+
+If you have questions or concerns, reach out to the person who sent the invitation or reply to this email.
+
+
+THANK YOU
+.Gov helps the public identify official, trusted information. Thank you for using a .gov domain.
+
+----------------------------------------------------------------
+
+The .gov team
+Contact us: <https://get.gov/contact/>
+Learn about .gov <https://get.gov>
+
+The .gov registry is a part of the Cybersecurity and Infrastructure Security Agency
+(CISA) <https://cisa.gov/>
+{% endautoescape %}

src/registrar/templates/emails/portfolio_admin_addition_notification_subject.txt

@@ -0,0 +1 @@
+An admin was invited to your .gov organization

src/registrar/utility/email_invitations.py

@@ -1,6 +1,8 @@
 from datetime import date
 from django.conf import settings
 from registrar.models import Domain, DomainInvitation, UserDomainRole
+from registrar.models.user_portfolio_permission import UserPortfolioPermission
+from registrar.models.utility.portfolio_helper import UserPortfolioRoleChoices
 from registrar.utility.errors import (
     AlreadyDomainInvitedError,
     AlreadyDomainManagerError,
@@ -169,7 +171,7 @@ def send_invitation_email(email, requestor_email, domains, requested_user):
         raise EmailSendingError(f"Could not send email invitation to {email} for domains: {domain_names}") from err
 
 
-def send_portfolio_invitation_email(email: str, requestor, portfolio):
+def send_portfolio_invitation_email(email: str, requestor, portfolio, is_admin_invitation):
     """
     Sends a portfolio member invitation email to the specified address.
 
@@ -179,6 +181,10 @@ def send_portfolio_invitation_email(email: str, requestor, portfolio):
         email (str): Email address of the recipient
         requestor (User): The user initiating the invitation.
         portfolio (Portfolio): The portfolio object for which the invitation is being sent.
+        is_admin_invitation (boolean): boolean indicating if the invitation is an admin invitation
+
+    Returns:
+        Boolean indicating if all messages were sent successfully.
 
     Raises:
         MissingEmailError: If the requestor has no email associated with their account.
@@ -210,3 +216,53 @@ def send_portfolio_invitation_email(email: str, requestor, portfolio):
         raise EmailSendingError(
             f"Could not sent email invitation to {email} for portfolio {portfolio}. Portfolio invitation not saved."
         ) from err
+
+    all_admin_emails_sent = True
+    # send emails to portfolio admins
+    if is_admin_invitation:
+        all_admin_emails_sent = send_portfolio_admin_addition_emails_to_portfolio_admins(
+            email=email,
+            requestor_email=requestor_email,
+            portfolio=portfolio,
+            requested_user=None,
+        )
+    return all_admin_emails_sent
+
+
+def send_portfolio_admin_addition_emails_to_portfolio_admins(
+    email: str, requestor_email, portfolio: Domain, requested_user=None
+):
+    """
+    Notifies all portfolio admins of the provided portfolio of a newly invited portfolio admin
+
+    Returns:
+        Boolean indicating if all messages were sent successfully.
+    """
+    all_emails_sent = True
+    # Get each portfolio admin from list
+    user_portfolio_permissions = UserPortfolioPermission.objects.filter(
+        portfolio=portfolio, roles__contains=[UserPortfolioRoleChoices.ORGANIZATION_ADMIN]
+    ).exclude(user__email=email)
+    for user_portfolio_permission in user_portfolio_permissions:
+        # Send email to each portfolio_admin
+        user = user_portfolio_permission.user
+        try:
+            send_templated_email(
+                "emails/portfolio_admin_addition_notification.txt",
+                "emails/portfolio_admin_addition_notification_subject.txt",
+                to_address=user.email,
+                context={
+                    "portfolio": portfolio,
+                    "requestor_email": requestor_email,
+                    "invited_email_address": email,
+                    "portfolio_admin": user,
+                    "date": date.today(),
+                },
+            )
+        except EmailSendingError:
+            logger.warning(
+                f"Could not send email organization admin notification to {user.email} for portfolio: {portfolio.name}",
+                exc_info=True,
+            )
+        all_emails_sent = False
+    return all_emails_sent

src/registrar/views/portfolios.py

@@ -773,12 +773,19 @@ class PortfolioAddMemberView(PortfolioMembersPermissionView, FormMixin):
         requested_email = form.cleaned_data["email"]
         requestor = self.request.user
         portfolio = form.cleaned_data["portfolio"]
+        is_admin_invitation = UserPortfolioRoleChoices.ORGANIZATION_ADMIN in form.cleaned_data["roles"]
 
         requested_user = User.objects.filter(email=requested_email).first()
         permission_exists = UserPortfolioPermission.objects.filter(user=requested_user, portfolio=portfolio).exists()
         try:
             if not requested_user or not permission_exists:
-                send_portfolio_invitation_email(email=requested_email, requestor=requestor, portfolio=portfolio)
+                if not send_portfolio_invitation_email(
+                    email=requested_email,
+                    requestor=requestor,
+                    portfolio=portfolio,
+                    is_admin_invitation=is_admin_invitation,
+                ):
+                    messages.warning(self.request, "Could not send email notification to existing organization admins.")
                 portfolio_invitation = form.save()
                 # if user exists for email, immediately retrieve portfolio invitation upon creation
                 if requested_user is not None:
@@ -801,7 +808,7 @@ class PortfolioAddMemberView(PortfolioMembersPermissionView, FormMixin):
                 portfolio,
                 exc_info=True,
             )
-            messages.warning(self.request, "Could not send portfolio email invitation.")
+            messages.error(self.request, "Could not send organization invitation email.")
         elif isinstance(exception, MissingEmailError):
             messages.error(self.request, str(exception))
             logger.error(