diff --git a/config.toml.sample b/config.toml.sample
index 9b29c700b..535edd939 100644
--- a/config.toml.sample
+++ b/config.toml.sample
@@ -84,6 +84,11 @@ max_idle = 10
         username = "xxxxx"
         password = ""
 
+        # Optional. Some SMTP servers require a FQDN in the hostname.
+        # By default, HELLOs go with "localhost". Set this if a custom
+        # hostname should be used.
+        hello_hostname = ""
+
         # Maximum time (milliseconds) to wait per e-mail push.
         send_timeout = 5000
 
diff --git a/go.mod b/go.mod
index bb829e471..aa594c994 100644
--- a/go.mod
+++ b/go.mod
@@ -30,4 +30,6 @@ require (
 	gopkg.in/volatiletech/null.v6 v6.0.0-20170828023728-0bef4e07ae1b
 )
 
+replace github.com/jordan-wright/email => github.com/knadh/email v0.0.0-20200206100304-6d2c7064c2e8
+
 go 1.13
diff --git a/go.sum b/go.sum
index 10966391c..65e59acd7 100644
--- a/go.sum
+++ b/go.sum
@@ -24,6 +24,10 @@ github.com/jmoiron/sqlx v1.2.0 h1:41Ip0zITnmWNR/vHV+S4m+VoUivnWY5E4OJfLZjCJMA=
 github.com/jmoiron/sqlx v1.2.0/go.mod h1:1FEQNm3xlJgrMD+FBdI9+xvCksHtbpVBBw5dYhBSsks=
 github.com/jordan-wright/email v0.0.0-20181027021455-480bedc4908b h1:veTPVnbkOijplSJVywDYKDRPoZEN39kfuMDzzRKP0FA=
 github.com/jordan-wright/email v0.0.0-20181027021455-480bedc4908b/go.mod h1:1c7szIrayyPPB/987hsnvNzLushdWf4o/79s3P08L8A=
+github.com/knadh/email v0.0.0-20181027021455-480bedc4908b h1:EJPKWXCv9G08Gs5KWjUP8PKj8trrRsLO8B90KZycApE=
+github.com/knadh/email v0.0.0-20181027021455-480bedc4908b/go.mod h1:xqJp94kA9qz2ffXuDJueBN+K6MP5BfEGmbIHR8MDJOo=
+github.com/knadh/email v0.0.0-20200206100304-6d2c7064c2e8 h1:HVq7nA5uWjpo93WsWjva1YIBuQrr8UkWQEUbzg1DX+E=
+github.com/knadh/email v0.0.0-20200206100304-6d2c7064c2e8/go.mod h1:Fy2gCFfZhay8jplf/Csj6cyH/oshQTkLQYZbKkcV+SY=
 github.com/knadh/goyesql v1.1.1 h1:iQLgsjYI/zC417DhmZYxmJgWmCHhtV4fho5QazWL/1g=
 github.com/knadh/goyesql v1.1.1/go.mod h1:W0tSzU8l7lYH1Fihj+bdQzkzOwvirrsMNHwkuY22qoY=
 github.com/knadh/goyesql v2.0.0+incompatible h1:hJFJrU8kaiLmvYt9I/1k1AB7q+qRhHs/afzTfQ3eGqk=
diff --git a/messenger/emailer.go b/messenger/emailer.go
index 80df9c37c..36f12911b 100644
--- a/messenger/emailer.go
+++ b/messenger/emailer.go
@@ -13,14 +13,15 @@ const emName = "email"
 
 // Server represents an SMTP server's credentials.
 type Server struct {
-	Name         string
-	Host         string        `koanf:"host"`
-	Port         int           `koanf:"port"`
-	AuthProtocol string        `koanf:"auth_protocol"`
-	Username     string        `koanf:"username"`
-	Password     string        `koanf:"password"`
-	SendTimeout  time.Duration `koanf:"send_timeout"`
-	MaxConns     int           `koanf:"max_conns"`
+	Name          string
+	Host          string        `koanf:"host"`
+	Port          int           `koanf:"port"`
+	AuthProtocol  string        `koanf:"auth_protocol"`
+	Username      string        `koanf:"username"`
+	Password      string        `koanf:"password"`
+	HelloHostname string        `koanf:"hello_hostname"`
+	SendTimeout   time.Duration `koanf:"send_timeout"`
+	MaxConns      int           `koanf:"max_conns"`
 
 	mailer *email.Pool
 }
@@ -52,6 +53,11 @@ func NewEmailer(srv ...Server) (Messenger, error) {
 			return nil, err
 		}
 
+		// Optional SMTP HELLO hostname.
+		if server.HelloHostname != "" {
+			pool.SetHelloHostname(server.HelloHostname)
+		}
+
 		s.mailer = pool
 		e.servers[s.Name] = &s
 		e.serverNames = append(e.serverNames, s.Name)