diff --git a/shard.yml b/shard.yml
index b8dc65f..96b2d16 100644
--- a/shard.yml
+++ b/shard.yml
@@ -12,9 +12,11 @@ targets:
   authd:
     main: src/main.cr
 
-crystal: 0.27
+crystal: 0.31
 
 dependencies:
+    grok:
+        github: spinscale/grok.cr
     passwd:
         git: https://git.karchnu.fr/WeirdOS/passwd.cr
         branch: master
diff --git a/src/authd.cr b/src/authd.cr
index 8ef2116..b253ced 100644
--- a/src/authd.cr
+++ b/src/authd.cr
@@ -417,9 +417,13 @@ module AuthD
 			end
 		end
 
-		def register(login : String, password : String, profile : JSON::Any?) : ::AuthD::User::Public?
-			send Request::Register.new login, password, profile
+		def register(login : String,
+			password : String,
+			email : String?,
+			phone : String?,
+			profile : JSON::Any?) : ::AuthD::User::Public?
 
+			send Request::Register.new login, password, email, phone, profile
 			response = Response.from_ipc read
 
 			case response
diff --git a/src/main.cr b/src/main.cr
index 08e8203..afcaa1b 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -6,6 +6,8 @@ require "jwt"
 require "ipc"
 require "dodb"
 
+require "grok"
+
 require "./authd.cr"
 
 extend AuthD
@@ -62,6 +64,8 @@ class AuthD::Service
 
 			Response::Token.new token.to_s @jwt_key
 		when Request::AddUser
+			# No verification of the users' informations when an admin adds it.
+			# No mail address verification.
 			if request.shared_key != @jwt_key
 				return Response::Error.new "invalid authentication key"
 			end
@@ -79,7 +83,7 @@ class AuthD::Service
 			uid = new_uid
 
 			user = User.new uid, request.login, password_hash
-			user.contact.email = request.email
+			user.contact.email = request.email unless request.email.nil?
 			user.contact.phone = request.phone unless request.phone.nil?
 
 			request.profile.try do |profile|
@@ -88,18 +92,6 @@ class AuthD::Service
 
 			@users << user
 
-			# Once the user is created and stored, we try to contact him
-			# TODO: send a mail
-			unless Process.run("activation-mailer", [
-				"-l", user.login,
-				"-e", user.contact.email.not_nil!,
-				"-t", "Activation email",
-				"-f", "karchnu@localhost",
-				"-a", user.contact.activation_key.not_nil!
-				]).success?
-				return Response::Error.new "cannot contact the user"
-			end
-
 			Response::UserAdded.new user.to_public
 		when Request::ValidateUser
 			if request.shared_key != @jwt_key
@@ -178,10 +170,27 @@ class AuthD::Service
 				return Response::Error.new "login already used"
 			end
 
+			if @require_email && request.email.nil?
+				return Response::Error.new "email required"
+			end
+
+			if ! request.email.nil?
+				# Test on the email address format.
+				grok = Grok.new [ "%{EMAILADDRESS:email}" ]
+				result = grok.parse request.email.not_nil!
+				email = result["email"]?
+
+				if email.nil?
+					return Response::Error.new "invalid email format"
+				end
+			end
+
 			uid = new_uid
 			password = hash_password request.password
 
 			user = User.new uid, request.login, password
+			user.contact.email = request.email unless request.email.nil?
+			user.contact.phone = request.phone unless request.phone.nil?
 
 			request.profile.try do |profile|
 				user.profile = profile
@@ -189,6 +198,17 @@ class AuthD::Service
 
 			@users << user
 
+			# Once the user is created and stored, we try to contact him
+			unless Process.run("activation-mailer", [
+				"-l", user.login,
+				"-e", user.contact.email.not_nil!,
+				"-t", "Activation email",
+				"-f", "karchnu@localhost",
+				"-a", user.contact.activation_key.not_nil!
+				]).success?
+				return Response::Error.new "cannot contact the user (but still registered)"
+			end
+
 			Response::UserAdded.new user.to_public
 		when Request::UpdatePassword
 			user = @users_per_login.get? request.login