diff --git a/fetcher/fetcher.go b/fetcher/fetcher.go
index 92f59c57c14cace441d7f2113d8daeba6d657927..40e0b91e6e5158d18a68d424482ced7981074296 100644
--- a/fetcher/fetcher.go
+++ b/fetcher/fetcher.go
@@ -264,6 +264,7 @@ func connectWithOptions(account *config.Account, extraOpts *imapclient.Options)
 		TLSConfig: &tls.Config{
 			ServerName:         imapServer,
 			InsecureSkipVerify: account.Insecure,
+			MinVersion:         tls.VersionTLS12,
 		},
 	}
 	if extraOpts != nil {
diff --git a/sender/sender.go b/sender/sender.go
index 872850dd24d087189195740f4b2758c2f137b79b..caba62d1e281b873a905b2ae25c65d1b1de5f125 100644
--- a/sender/sender.go
+++ b/sender/sender.go
@@ -637,6 +637,7 @@ func SendEmail(account *config.Account, to, cc, bcc []string, subject, plainBody
 	tlsConfig := &tls.Config{
 		ServerName:         smtpServer,
 		InsecureSkipVerify: account.Insecure,
+		MinVersion:         tls.VersionTLS12,
 	}
 
 	var c *smtp.Client
@@ -834,6 +835,7 @@ func SendCalendarReply(account *config.Account, to []string, subject, plainBody
 	tlsConfig := &tls.Config{
 		ServerName:         smtpServer,
 		InsecureSkipVerify: account.Insecure,
+		MinVersion:         tls.VersionTLS12,
 	}
 
 	var c *smtp.Client