diff --git a/go.mod b/go.mod
index d1499d6..ca18885 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module mailcatcher
 go 1.18
 
 require (
-	github.com/emersion/go-smtp v0.21.2
+	github.com/emersion/go-smtp v0.21.3
 	github.com/go-playground/locales v0.14.1
 	github.com/go-playground/universal-translator v0.18.1
 	github.com/tkanos/gonfig v0.0.0-20181112185242-896f3d81fadf
diff --git a/go.sum b/go.sum
index 516aed4..21e88b0 100644
--- a/go.sum
+++ b/go.sum
@@ -2,8 +2,8 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 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 v0.21.2 h1:OLDgvZKuofk4em9fT5tFG5j4jE1/hXnX75UMvcrL4AA=
-github.com/emersion/go-smtp v0.21.2/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
+github.com/emersion/go-smtp v0.21.3 h1:7uVwagE8iPYE48WhNsng3RRpCUpFvNl39JGNSIyGVMY=
+github.com/emersion/go-smtp v0.21.3/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
 github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=