diff --git a/bin/addcourse b/bin/addcourse
index 79c1bcbbc7..ecbc9b0ded 100755
--- a/bin/addcourse
+++ b/bin/addcourse
@@ -58,7 +58,7 @@ BEGIN {
 use lib "$ENV{WEBWORK_ROOT}/lib";
 
 use WeBWorK::CourseEnvironment;
-use WeBWorK::Utils                   qw(runtime_use cryptPassword);
+use WeBWorK::Utils                   qw(runtime_use cryptPassword isValidEmailAddress);
 use WeBWorK::Utils::CourseManagement qw(addCourse);
 use WeBWorK::File::Classlist         qw(parse_classlist);
 use WeBWorK::DB::Record::User;
@@ -101,6 +101,14 @@ if ($users) {
 		my %record  = %$record;
 		my $user_id = $record{user_id};
 
+		if (defined $record{email_address}
+			&& $record{email_address} ne ''
+			&& !isValidEmailAddress($record{email_address}))
+		{
+			warn qq{Invalid email address "$record{email_address}" for user $user_id will not be set.\n};
+			$record{email_address} = '';
+		}
+
 		# Set the default status if the status field is not set.
 		$record{status} = $ce->{statuses}{Enrolled}{abbrevs}[0] unless $record{status};
 
diff --git a/bin/importClassList.pl b/bin/importClassList.pl
index 52316f17cf..e175e31fce 100755
--- a/bin/importClassList.pl
+++ b/bin/importClassList.pl
@@ -17,7 +17,7 @@ BEGIN
 
 use WeBWorK::DB              qw(check_user_id);
 use WeBWorK::File::Classlist qw(parse_classlist);
-use WeBWorK::Utils           qw(cryptPassword);
+use WeBWorK::Utils           qw(cryptPassword isValidEmailAddress);
 use WeBWorK::File::Classlist qw(parse_classlist);
 
 if ((scalar(@ARGV) != 2)) {
@@ -89,6 +89,14 @@ sub importUsersFromCSV {
 			next;
 		}
 
+		if (defined $record{email_address}
+			&& $record{email_address} ne ''
+			&& !isValidEmailAddress($record{email_address}))
+		{
+			warn "Invalid email address '$record{email_address}' for user $user_id will not be set.\n";
+			$record{email_address} = '';
+		}
+
 		# set default status is status field is "empty"
 		$record{status} = $default_status_abbrev
 			unless defined $record{status} and $record{status} ne "";
diff --git a/lib/WeBWorK/ContentGenerator/API/CourseActions.pm b/lib/WeBWorK/ContentGenerator/API/CourseActions.pm
index 3d5eaefa73..9552b73aae 100644
--- a/lib/WeBWorK/ContentGenerator/API/CourseActions.pm
+++ b/lib/WeBWorK/ContentGenerator/API/CourseActions.pm
@@ -8,7 +8,7 @@ use Mojo::JSON            qw(false true);
 
 use WeBWorK::DB;
 use WeBWorK::DB::Utils               qw(initializeUserProblem);
-use WeBWorK::Utils                   qw(cryptPassword);
+use WeBWorK::Utils                   qw(cryptPassword isValidEmailAddress);
 use WeBWorK::Utils::CourseManagement qw(addCourse);
 use WeBWorK::Utils::Files            qw(surePathToFile path_is_subdir);
 use WeBWorK::ConfigValues            qw(getConfigValues);
@@ -133,6 +133,9 @@ sub addUser ($c) {
 		# Add a new user.
 		my $ce = $c->ce;
 
+		return $c->renderError('The email_address parameter is not a valid email address.')
+			if $c->req->param('email_address') && !isValidEmailAddress($c->req->param('email_address'));
+
 		my $new_student =
 			$db->newUser(user_id => $c->req->param('user_id'), status => $ce->{statuses}{Enrolled}{abbrevs}[0]);
 		$new_student->first_name($c->req->param('first_name'))       if $c->req->param('first_name');
diff --git a/lib/WeBWorK/ContentGenerator/CourseAdmin.pm b/lib/WeBWorK/ContentGenerator/CourseAdmin.pm
index eef18d5af9..5738232c6f 100644
--- a/lib/WeBWorK/ContentGenerator/CourseAdmin.pm
+++ b/lib/WeBWorK/ContentGenerator/CourseAdmin.pm
@@ -15,7 +15,7 @@ use Time::localtime;
 
 use WeBWorK::CourseEnvironment;
 use WeBWorK::Debug                   qw(debug);
-use WeBWorK::Utils                   qw(cryptPassword trim_spaces);
+use WeBWorK::Utils                   qw(cryptPassword trim_spaces isValidEmailAddress);
 use WeBWorK::Utils::CourseManagement qw(
 	addCourse
 	renameCourse
@@ -275,6 +275,10 @@ sub add_course_validate ($c) {
 					$_
 				);
 		}
+
+		my $email = trim_spaces($c->param("add_initial_email_$_"));
+		push @errors, $c->maketext('The email address for user number [_1] is not valid.', $_)
+			if $email ne '' && !isValidEmailAddress($email);
 	}
 
 	return @errors;
diff --git a/lib/WeBWorK/ContentGenerator/Feedback.pm b/lib/WeBWorK/ContentGenerator/Feedback.pm
index ee77fbe4d8..21569e5e42 100644
--- a/lib/WeBWorK/ContentGenerator/Feedback.pm
+++ b/lib/WeBWorK/ContentGenerator/Feedback.pm
@@ -12,7 +12,7 @@ use Email::Stuffer;
 use Try::Tiny;
 
 use WeBWorK::Upload;
-use WeBWorK::Utils qw(createEmailSenderTransportSMTP fetchEmailRecipients formatEmailSubject);
+use WeBWorK::Utils qw(createEmailSenderTransportSMTP fetchEmailRecipients formatEmailSubject isValidEmailAddress);
 
 # request parameters used
 #
@@ -91,7 +91,7 @@ sub initialize ($c) {
 			$c->stash->{send_error} = $c->maketext('No Sender specified.');
 			return;
 		}
-		unless ($from =~ /^[a-zA-Z0-9.!#$%&\'*+\/=?^_`~\-]+@[a-zA-Z0-9\-]+\.[a-zA-Z0-9.\-]+$/) {
+		unless (isValidEmailAddress($from)) {
 			$c->stash->{send_error} = $c->maketext('Sender is not a valid email address.');
 			return;
 		}
diff --git a/lib/WeBWorK/ContentGenerator/Instructor/AddUsers.pm b/lib/WeBWorK/ContentGenerator/Instructor/AddUsers.pm
index d4543315aa..b5935578cc 100644
--- a/lib/WeBWorK/ContentGenerator/Instructor/AddUsers.pm
+++ b/lib/WeBWorK/ContentGenerator/Instructor/AddUsers.pm
@@ -7,7 +7,7 @@ WeBWorK::ContentGenerator::Instructor::AddUsers - Menu interface for adding user
 
 =cut
 
-use WeBWorK::Utils             qw/cryptPassword trim_spaces/;
+use WeBWorK::Utils             qw/cryptPassword trim_spaces isValidEmailAddress/;
 use WeBWorK::Utils::Instructor qw(assignSetsToUsers);
 
 sub initialize ($c) {
@@ -48,7 +48,11 @@ sub initialize ($c) {
 			$newUser->comment(trim_spaces($c->param("comment_$i")));
 			$newUser->status($c->param("status_$i"));
 
-			eval { $db->addUser($newUser) };
+			eval {
+				die $c->maketext('Invalid email address.') . "\n"
+					if $newUser->email_address ne '' && !isValidEmailAddress($newUser->email_address);
+				$db->addUser($newUser);
+			};
 			if ($@) {
 				push(
 					@{ $c->{studentEntryReport} },
diff --git a/lib/WeBWorK/ContentGenerator/Instructor/UserList.pm b/lib/WeBWorK/ContentGenerator/Instructor/UserList.pm
index c1fe85a1f4..18b5ee9fab 100644
--- a/lib/WeBWorK/ContentGenerator/Instructor/UserList.pm
+++ b/lib/WeBWorK/ContentGenerator/Instructor/UserList.pm
@@ -48,7 +48,7 @@ Export users:
 use Mojo::File;
 
 use WeBWorK::File::Classlist qw(parse_classlist write_classlist);
-use WeBWorK::Utils           qw(cryptPassword x);
+use WeBWorK::Utils           qw(cryptPassword isValidEmailAddress x);
 
 use constant HIDE_USERS_THRESHOLD => 200;
 use constant EDIT_FORMS           => [qw(save_edit cancel_edit)];
@@ -106,11 +106,21 @@ use constant FIELDS => [
 # a subroutine that takes the parameter value as its only argument, and returns a translatable error string if the
 # parameter value is not valid for the field, and 0 otherwise.
 use constant FIELD_PROPERTIES => {
-	user_id                   => { name => x('Login Name') },
-	first_name                => { name => x('First Name'),        type => 'text', attributes => { size => 10 } },
-	last_name                 => { name => x('Last Name'),         type => 'text', attributes => { size => 10 } },
-	email_address             => { name => x('Email Address'),     type => 'text', attributes => { size => 20 } },
-	student_id                => { name => x('Student ID'),        type => 'text', attributes => { size => 11 } },
+	user_id       => { name => x('Login Name') },
+	first_name    => { name => x('First Name'), type => 'text', attributes => { size => 10 } },
+	last_name     => { name => x('Last Name'),  type => 'text', attributes => { size => 10 } },
+	email_address => {
+		name         => x('Email Address'),
+		type         => 'text',
+		attributes   => { size => 20 },
+		perlValidate => sub {
+			my $value = shift;
+			return $value =~ /\S/ && !isValidEmailAddress($value)
+				? (x('Email address for [_1] unchanged. The value given is not a valid email address.'))[0]
+				: 0;
+		}
+	},
+	student_id                => { name => x('Student ID'), type => 'text', attributes => { size => 11 } },
 	status                    => { name => x('Enrollment Status'), type => 'status' },
 	accommodation_time_factor => {
 		name       => x('Accommodation Time Factor'),
@@ -709,7 +719,7 @@ sub importUsersFromCSV ($c, $fileName, $replaceExisting, $fallbackPasswordSource
 	my $default_permission_level = $ce->{default_permission_level};
 
 	my (@usersToInsert, @passwordsToInsert, @permissionsToInsert,
-		@usersToUpdate, @passwordsToUpdate, @permissionsToUpdate, @skipped);
+		@usersToUpdate, @passwordsToUpdate, @permissionsToUpdate, @skipped, @invalidEmailUsers);
 
 	# get list of hashrefs representing lines in classlist file
 	my @classlist = parse_classlist("$ce->{courseDirs}{templates}/$fileName");
@@ -739,6 +749,14 @@ sub importUsersFromCSV ($c, $fileName, $replaceExisting, $fallbackPasswordSource
 			next;
 		}
 
+		if (defined $record{email_address}
+			&& $record{email_address} ne ''
+			&& !isValidEmailAddress($record{email_address}))
+		{
+			push @invalidEmailUsers, $user_id;
+			$record{email_address} = '';
+		}
+
 		# set default status is status field is "empty"
 		$record{status} = $default_status_abbrev
 			unless defined $record{status} && $record{status} ne '';
@@ -789,6 +807,14 @@ sub importUsersFromCSV ($c, $fileName, $replaceExisting, $fallbackPasswordSource
 		}
 	}
 
+	$c->addbadmessage($c->maketext(
+		'The email [plural,_1,address was,addresses were] not valid for the following [plural,_1,user,users] '
+			. 'and [plural,_1,was,were] not set: [_2]',
+		scalar(@invalidEmailUsers),
+		join(', ', @invalidEmailUsers)
+	))
+		if @invalidEmailUsers;
+
 	$db->User->insert_records(\@usersToInsert)                  if @usersToInsert;
 	$db->User->update_records(\@usersToUpdate)                  if @usersToUpdate;
 	$db->Password->insert_records(\@passwordsToInsert)          if @passwordsToInsert;
diff --git a/lib/WeBWorK/ContentGenerator/Options.pm b/lib/WeBWorK/ContentGenerator/Options.pm
index 7208281f4d..dbc66c29aa 100644
--- a/lib/WeBWorK/ContentGenerator/Options.pm
+++ b/lib/WeBWorK/ContentGenerator/Options.pm
@@ -7,7 +7,7 @@ WeBWorK::ContentGenerator::Options - Change user options.
 
 =cut
 
-use WeBWorK::Utils qw(cryptPassword utf8Crypt);
+use WeBWorK::Utils qw(cryptPassword utf8Crypt isValidEmailAddress);
 use WeBWorK::Localize;
 
 sub page_title ($c) {
@@ -128,17 +128,24 @@ sub initialize ($c) {
 
 	my $newA = $c->param('newAddress');
 	if ($changeOptions && $authz->hasPermissions($userID, 'change_email_address') && $newA) {
-		my $oldA = $c->{effectiveUser}->email_address;
-		$c->{effectiveUser}->email_address($newA);
-		eval { $db->putUser($c->{effectiveUser}) };
-		if ($@) {
-			$c->{effectiveUser}->email_address($oldA);
-			$c->log->error("Unable to save new email address for $userID: $@");
-			$c->addbadmessage($c->maketext('Your email address has not been changed due to an internal error.'));
+		if (!isValidEmailAddress($newA)) {
+			$c->addbadmessage(
+				$c->maketext(
+					'Your email address has not been changed. The new email address you entered is not valid.')
+			);
 		} else {
-			$c->param('currAddress', $c->param('newAddress'));
-			$c->param('newAddress',  undef);
-			$c->addgoodmessage($c->maketext('Your email address has been changed.'));
+			my $oldA = $c->{effectiveUser}->email_address;
+			$c->{effectiveUser}->email_address($newA);
+			eval { $db->putUser($c->{effectiveUser}) };
+			if ($@) {
+				$c->{effectiveUser}->email_address($oldA);
+				$c->log->error("Unable to save new email address for $userID: $@");
+				$c->addbadmessage($c->maketext('Your email address has not been changed due to an internal error.'));
+			} else {
+				$c->param('currAddress', $newA);
+				$c->param('newAddress',  undef);
+				$c->addgoodmessage($c->maketext('Your email address has been changed.'));
+			}
 		}
 	}
 
diff --git a/lib/WeBWorK/Utils.pm b/lib/WeBWorK/Utils.pm
index a9fee1d831..de42b34be0 100644
--- a/lib/WeBWorK/Utils.pm
+++ b/lib/WeBWorK/Utils.pm
@@ -1,6 +1,7 @@
 package WeBWorK::Utils;
 use Mojo::Base 'Exporter', -signatures;
 
+use Email::Address::XS;
 use Email::Sender::Transport::SMTP;
 use Mojo::JSON qw(from_json to_json);
 use Mojo::Util qw(b64_encode b64_decode encode decode);
@@ -31,6 +32,7 @@ our @EXPORT_OK = qw(
 	fetchEmailRecipients
 	processEmailMessage
 	createEmailSenderTransportSMTP
+	isValidEmailAddress
 	generateURLs
 	formatEmailSubject
 	getAssetURL
@@ -373,6 +375,10 @@ sub createEmailSenderTransportSMTP ($ce) {
 	});
 }
 
+sub isValidEmailAddress ($address) {
+	return Email::Address::XS->parse_bare_address($address // '')->is_valid;
+}
+
 sub generateURLs ($c, %params) {
 	my $db       = $c->db;
 	my $userName = $c->param('user');
@@ -803,6 +809,12 @@ Usage: C<createEmailSenderTransportSMTP($ce)>
 This returns an C<Email::Sender::Transport::SMTP> object for use in sending
 emails. A valid C<WeBWorK::CourseEnvironment> object must be provided in C<$ce>.
 
+=head2 isValidEmailAddress
+
+Usage: C<isValidEmailAddress($address)>
+
+Returns true if C<$address> is a valid email address, and false otherwise.
+
 =head2 generateURLs
 
 Usage: C<generateURLs($c, %params)>