diff --git a/go.mod b/go.mod
index dfc0cc9f..77d1772a 100644
--- a/go.mod
+++ b/go.mod
@@ -16,7 +16,7 @@ require (
 	github.com/cenkalti/backoff v2.2.1+incompatible
 	github.com/d4l3k/messagediff v1.2.2-0.20190829033028-7e0a312ae40b
 	github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21
-	github.com/emersion/go-smtp v0.14.0
+	github.com/emersion/go-smtp v0.16.0
 	github.com/google/go-cmp v0.5.9
 	github.com/google/subcommands v1.2.0
 	github.com/google/uuid v1.3.0
diff --git a/go.sum b/go.sum
index 365f4a8f..b33e9566 100644
--- a/go.sum
+++ b/go.sum
@@ -341,8 +341,8 @@ github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4
 github.com/elazarl/goproxy v0.0.0-20220529153421-8ea89ba92021 h1:EbF0UihnxWRcIMOwoVtqnAylsqcjzqpSvMdjF2Ud4rA=
 github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 h1:OJyUGMJTzHTd1XQp98QTaHernxMYzRaOasRir9hUlFQ=
 github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
-github.com/emersion/go-smtp v0.14.0 h1:RYW203p+EcPjL8Z/ZpT9lZ6iOc8MG1MQzEx1UKEkXlA=
-github.com/emersion/go-smtp v0.14.0/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
+github.com/emersion/go-smtp v0.16.0 h1:eB9CY9527WdEZSs5sWisTmilDX7gG+Q/2IdRcmubpa8=
+github.com/emersion/go-smtp v0.16.0/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
 github.com/emicklei/go-restful/v3 v3.8.0 h1:eCZ8ulSerjdAiaNpF7GxXIE7ZCMo1moN1qX+S609eVw=
 github.com/emirpasic/gods v1.18.1 h1:FXtiHYKDGKCW2KzwZKx0iC0PQmdlorYgdFG9jPXJ1Bc=
 github.com/emirpasic/gods v1.18.1/go.mod h1:8tpGGwCnJ5H4r6BWwaV6OrWmMoPhUl5jm/FMNAnJvWQ=