diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
index f58bb062fe..40b6c041f0 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -50,6 +50,7 @@
"invite_from_person_to_space": "[%(app)s] %(person)s has invited you to join the %(space)s space on %(app)s...",
"password_reset": "[%(server_name)s] Password reset",
"email_validation": "[%(server_name)s] Validate your email",
+ "email_already_in_use": "[%(server_name)s] Email already in use",
}
LEGACY_TEMPLATE_DIR_WARNING = """
@@ -74,6 +75,7 @@ class EmailSubjectConfig:
invite_from_person_to_space: str
password_reset: str
email_validation: str
+ email_already_in_use: str
class EmailConfig(Config):
@@ -178,6 +180,12 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
registration_template_text = email_config.get(
"registration_template_text", "registration.txt"
)
+ already_in_use_template_html = email_config.get(
+ "already_in_use_template_html", "already_in_use.html"
+ )
+ already_in_use_template_text = email_config.get(
+ "already_in_use_template_html", "already_in_use.txt"
+ )
add_threepid_template_html = email_config.get(
"add_threepid_template_html", "add_threepid.html"
)
@@ -213,6 +221,8 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
self.email_password_reset_template_text,
self.email_registration_template_html,
self.email_registration_template_text,
+ self.email_already_in_use_template_html,
+ self.email_already_in_use_template_text,
self.email_add_threepid_template_html,
self.email_add_threepid_template_text,
self.email_password_reset_template_confirmation_html,
@@ -228,6 +238,8 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
password_reset_template_text,
registration_template_html,
registration_template_text,
+ already_in_use_template_html,
+ already_in_use_template_text,
add_threepid_template_html,
add_threepid_template_text,
"password_reset_confirmation.html",
diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py
index 0a174a5396..aa7cc15b03 100644
--- a/synapse/push/mailer.py
+++ b/synapse/push/mailer.py
@@ -189,6 +189,20 @@ async def send_registration_mail(
template_vars,
)
+ async def send_already_in_use_mail(self, email_address: str) -> None:
+ """Send an email if the address is already bound to an user account
+
+ Args:
+ email_address: Email address we're sending to the "already in use" mail
+ """
+
+ await self.send_email(
+ email_address,
+ self.email_subjects.email_already_in_use
+ % {"server_name": self.hs.config.server.server_name, "app": self.app_name},
+ {},
+ )
+
async def send_add_threepid_mail(
self, email_address: str, token: str, client_secret: str, sid: str
) -> None:
diff --git a/synapse/res/templates/already_in_use.html b/synapse/res/templates/already_in_use.html
new file mode 100644
index 0000000000..93efd45533
--- /dev/null
+++ b/synapse/res/templates/already_in_use.html
@@ -0,0 +1,12 @@
+{% extends "_base.html" %}
+{% block title %}Email already in use{% endblock %}
+
+{% block body %}
+You have asked us to register this email with a new Matrix account, but this email is already registered with an existing account.
+
+Please reset your password if needed.
+
+If this was not you, you can safely disregard this email.
+
+Thank you.
+{% endblock %}
diff --git a/synapse/res/templates/already_in_use.txt b/synapse/res/templates/already_in_use.txt
new file mode 100644
index 0000000000..c60401a940
--- /dev/null
+++ b/synapse/res/templates/already_in_use.txt
@@ -0,0 +1,10 @@
+Hello there,
+
+You have asked us to register this email with a new Matrix account,
+but this email is already registered with an existing account.
+
+Please reset your password if needed.
+
+If this was not you, you can safely disregard this email.
+
+Thank you.
diff --git a/synapse/rest/client/register.py b/synapse/rest/client/register.py
index b0c1ee44ef..f5d48650bb 100644
--- a/synapse/rest/client/register.py
+++ b/synapse/rest/client/register.py
@@ -84,12 +84,18 @@ def __init__(self, hs: "HomeServer"):
self.config = hs.config
if self.hs.config.email.can_verify_email:
- self.mailer = Mailer(
+ self.registration_mailer = Mailer(
hs=self.hs,
app_name=self.config.email.email_app_name,
template_html=self.config.email.email_registration_template_html,
template_text=self.config.email.email_registration_template_text,
)
+ self.already_in_use_mailer = Mailer(
+ hs=self.hs,
+ app_name=self.config.email.email_app_name,
+ template_html=self.config.email.email_already_in_use_template_html,
+ template_text=self.config.email.email_already_in_use_template_text,
+ )
async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
if not self.hs.config.email.can_verify_email:
@@ -137,8 +143,10 @@ async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
if self.hs.config.server.request_token_inhibit_3pid_errors:
# Make the client think the operation succeeded. See the rationale in the
# comments for request_token_inhibit_3pid_errors.
+ # Still send an email to warn the user that an account already exists.
# Also wait for some random amount of time between 100ms and 1s to make it
# look like we did something.
+ await self.already_in_use_mailer.send_already_in_use_mail(email)
await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
return 200, {"sid": random_string(16)}
@@ -149,7 +157,7 @@ async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
email,
client_secret,
send_attempt,
- self.mailer.send_registration_mail,
+ self.registration_mailer.send_registration_mail,
next_link,
)