diff --git a/src/domain/smtp.rs b/src/domain/smtp.rs
new file mode 100644
index 0000000..c5b969f
--- /dev/null
+++ b/src/domain/smtp.rs
@@ -0,0 +1,68 @@
+use anyhow::Result;
+use lettre::{
+    self,
+    transport::smtp::{
+        client::{Tls, TlsParameters},
+        SmtpTransport,
+    },
+    Transport,
+};
+
+use crate::domain::account::entity::Account;
+
+pub trait SmtpServiceInterface {
+    fn send(&mut self, msg: &lettre::Message) -> Result<()>;
+}
+
+pub struct SmtpService<'a> {
+    account: &'a Account,
+    transport: Option<SmtpTransport>,
+}
+
+impl<'a> SmtpService<'a> {
+    pub fn new(account: &'a Account) -> Result<Self> {
+        Ok(Self {
+            account,
+            transport: None,
+        })
+    }
+
+    fn transport(&mut self) -> Result<&SmtpTransport> {
+        if let Some(ref transport) = self.transport {
+            Ok(transport)
+        } else {
+            let builder = if self.account.smtp_starttls {
+                SmtpTransport::starttls_relay(&self.account.smtp_host)
+            } else {
+                SmtpTransport::relay(&self.account.smtp_host)
+            }?;
+
+            let tls = TlsParameters::builder(self.account.smtp_host.to_owned())
+                .dangerous_accept_invalid_hostnames(self.account.smtp_insecure)
+                .dangerous_accept_invalid_certs(self.account.smtp_insecure)
+                .build()?;
+            let tls = if self.account.smtp_starttls {
+                Tls::Required(tls)
+            } else {
+                Tls::Wrapper(tls)
+            };
+
+            self.transport = Some(
+                builder
+                    .tls(tls)
+                    .port(self.account.smtp_port)
+                    .credentials(self.account.smtp_creds()?)
+                    .build(),
+            );
+
+            Ok(self.transport.as_ref().unwrap())
+        }
+    }
+}
+
+impl<'a> SmtpServiceInterface for SmtpService<'a> {
+    fn send(&mut self, msg: &lettre::Message) -> Result<()> {
+        self.transport()?.send(msg)?;
+        Ok(())
+    }
+}
diff --git a/src/domain/smtp/mod.rs b/src/domain/smtp/mod.rs
deleted file mode 100644
index 81d6738..0000000
--- a/src/domain/smtp/mod.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-//! Modules related to SMTP.
-
-pub mod service;
diff --git a/src/domain/smtp/service.rs b/src/domain/smtp/service.rs
deleted file mode 100644
index 286e71a..0000000
--- a/src/domain/smtp/service.rs
+++ /dev/null
@@ -1,51 +0,0 @@
-use anyhow::Result;
-use lettre::{
-    self,
-    transport::{smtp::client::Tls, smtp::client::TlsParameters, smtp::SmtpTransport},
-    Transport,
-};
-
-use crate::domain::account::entity::Account;
-
-pub trait SMTPServiceInterface {
-    fn send(&self, msg: &lettre::Message) -> Result<()>;
-}
-
-pub struct SMTPService<'a> {
-    account: &'a Account,
-}
-
-impl<'a> SMTPService<'a> {
-    pub fn new(account: &'a Account) -> Result<Self> {
-        Ok(Self { account })
-    }
-}
-
-impl<'a> SMTPServiceInterface for SMTPService<'a> {
-    fn send(&self, msg: &lettre::Message) -> Result<()> {
-        let smtp_relay = if self.account.smtp_starttls {
-            SmtpTransport::starttls_relay
-        } else {
-            SmtpTransport::relay
-        };
-
-        let tls = TlsParameters::builder(self.account.smtp_host.to_string())
-            .dangerous_accept_invalid_hostnames(self.account.smtp_insecure)
-            .dangerous_accept_invalid_certs(self.account.smtp_insecure)
-            .build()?;
-        let tls = if self.account.smtp_starttls {
-            Tls::Required(tls)
-        } else {
-            Tls::Wrapper(tls)
-        };
-
-        smtp_relay(&self.account.smtp_host)?
-            .port(self.account.smtp_port)
-            .tls(tls)
-            .credentials(self.account.smtp_creds()?)
-            .build()
-            .send(msg)?;
-
-        Ok(())
-    }
-}
diff --git a/src/lib.rs b/src/lib.rs
index 61a963a..a6ae5ca 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -43,4 +43,5 @@ pub mod msg;
 pub mod output;
 
 pub mod domain;
+pub mod infra;
 pub mod ui;
diff --git a/src/main.rs b/src/main.rs
index bd03c07..b030cb9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,7 +8,7 @@ use himalaya::{
     comp,
     config::cli::config_args,
     ctx::Ctx,
-    domain::{account::entity::Account, config::entity::Config, smtp::service::SMTPService},
+    domain::{account::entity::Account, config::entity::Config, smtp::SmtpService},
     flag, imap, mbox, msg,
     output::{cli::output_args, model::Output},
 };
@@ -73,7 +73,7 @@ fn main() -> Result<()> {
 
     let account_name = arg_matches.value_of("account");
     let account = Account::try_from((&config, account_name))?;
-    let smtp_service = SMTPService::new(&account)?;
+    let smtp_service = SmtpService::new(&account)?;
     debug!("account name: {}", account_name.unwrap_or("default"));
     trace!("account: {:?}", account);
 
diff --git a/src/msg/cli.rs b/src/msg/cli.rs
index 937da98..81606b8 100644
--- a/src/msg/cli.rs
+++ b/src/msg/cli.rs
@@ -20,7 +20,7 @@ use super::{
 };
 use crate::{
     ctx::Ctx,
-    domain::{account::entity::Account, smtp},
+    domain::{account::entity::Account, smtp::*},
     flag::model::Flags,
     imap::model::ImapConnector,
     input,
@@ -127,10 +127,10 @@ pub fn subcmds<'a>() -> Vec<clap::App<'a, 'a>> {
     ]
 }
 
-pub fn matches<SMTP: smtp::service::SMTPServiceInterface>(
+pub fn matches<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     account: &Account,
-    smtp: SMTP,
+    smtp: SmtpService,
 ) -> Result<bool> {
     match ctx.arg_matches.subcommand() {
         ("attachments", Some(matches)) => msg_matches_attachments(&ctx, &account, &matches),
@@ -399,11 +399,11 @@ fn msg_matches_attachments(
     Ok(true)
 }
 
-fn msg_matches_write<'a, SMTP: smtp::service::SMTPServiceInterface>(
+fn msg_matches_write<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     account: &Account,
     matches: &clap::ArgMatches,
-    smtp: SMTP,
+    smtp: SmtpService,
 ) -> Result<bool> {
     debug!("write command matched");
 
@@ -438,11 +438,11 @@ fn msg_matches_write<'a, SMTP: smtp::service::SMTPServiceInterface>(
     Ok(true)
 }
 
-fn msg_matches_reply<'a, SMTP: smtp::service::SMTPServiceInterface>(
+fn msg_matches_reply<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     account: &Account,
     matches: &clap::ArgMatches,
-    smtp: SMTP,
+    smtp: SmtpService,
 ) -> Result<bool> {
     debug!("reply command matched");
 
@@ -473,11 +473,11 @@ fn msg_matches_reply<'a, SMTP: smtp::service::SMTPServiceInterface>(
     Ok(true)
 }
 
-pub fn msg_matches_mailto<'a, SMTP: smtp::service::SMTPServiceInterface>(
+pub fn msg_matches_mailto<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     account: &Account,
     url: &Url,
-    smtp: SMTP,
+    smtp: SmtpService,
 ) -> Result<()> {
     debug!("mailto command matched");
 
@@ -525,11 +525,11 @@ pub fn msg_matches_mailto<'a, SMTP: smtp::service::SMTPServiceInterface>(
     Ok(())
 }
 
-fn msg_matches_forward<'a, SMTP: smtp::service::SMTPServiceInterface>(
+fn msg_matches_forward<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     account: &Account,
     matches: &clap::ArgMatches,
-    smtp: SMTP,
+    smtp: SmtpService,
 ) -> Result<bool> {
     debug!("forward command matched");
 
@@ -639,11 +639,11 @@ fn msg_matches_delete(ctx: &Ctx, account: &Account, matches: &clap::ArgMatches)
     Ok(true)
 }
 
-fn msg_matches_send<'a, SMTP: smtp::service::SMTPServiceInterface>(
+fn msg_matches_send<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     account: &Account,
     matches: &clap::ArgMatches,
-    smtp: SMTP,
+    mut smtp: SmtpService,
 ) -> Result<bool> {
     debug!("send command matched");
 
@@ -849,11 +849,11 @@ fn tpl_matches_forward(ctx: &Ctx, account: &Account, matches: &clap::ArgMatches)
 
 /// This function opens the prompt to do some actions to the msg like sending, editing it again and
 /// so on.
-fn msg_interaction<SMTP: smtp::service::SMTPServiceInterface>(
+fn msg_interaction<SmtpService: SmtpServiceInterface>(
     ctx: &Ctx,
     msg: &mut Msg,
     imap_conn: &mut ImapConnector,
-    smtp: SMTP,
+    mut smtp: SmtpService,
 ) -> Result<bool> {
     // let the user change the body a little bit first, before opening the prompt
     msg.edit_body()?;