diff --git a/go.mod b/go.mod
index 30021c1..4735400 100644
--- a/go.mod
+++ b/go.mod
@@ -10,7 +10,7 @@ require (
 	github.com/creasty/defaults v1.7.0
 	github.com/docker/docker v26.0.0+incompatible
 	github.com/emersion/go-sasl v0.0.0-20220912192320-0145f2c60ead
-	github.com/emersion/go-smtp v0.20.2
+	github.com/emersion/go-smtp v0.21.0
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/jessevdk/go-flags v1.5.0
 	github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible
diff --git a/go.sum b/go.sum
index 30c607a..3331ba0 100644
--- a/go.sum
+++ b/go.sum
@@ -63,8 +63,8 @@ github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDD
 github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
 github.com/emersion/go-sasl v0.0.0-20220912192320-0145f2c60ead h1:fI1Jck0vUrXT8bnphprS1EoVRe2Q5CKCX8iDlpqjQ/Y=
 github.com/emersion/go-sasl v0.0.0-20220912192320-0145f2c60ead/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
-github.com/emersion/go-smtp v0.20.2 h1:peX42Qnh5Q0q3vrAnRy43R/JwTnnv75AebxbkTL7Ia4=
-github.com/emersion/go-smtp v0.20.2/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
+github.com/emersion/go-smtp v0.21.0 h1:ZDZmX9aFUuPlD1lpoT0nC/nozZuIkSCyQIyxdijjCy0=
+github.com/emersion/go-smtp v0.21.0/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
 github.com/felixge/httpsnoop v1.0.3 h1:s/nj+GCswXYzN5v2DpNMuMQYe+0DDwt5WVCU6CWBdXk=
 github.com/felixge/httpsnoop v1.0.3/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=