diff --unified -r --text sylpheed-3.7.0beta1/libsylph/ssl.c patched/libsylph/ssl.c
--- sylpheed-3.7.0beta1/libsylph/ssl.c	2019-08-16 09:34:58.296699900 +0300
+++ patched/libsylph/ssl.c	2019-08-16 09:40:01.656029709 +0300
@@ -260,6 +260,10 @@
 		return FALSE;
 	}
 
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+	SSL_set_tlsext_host_name(sockinfo->ssl, sockinfo->hostname);
+#endif
+
 	SSL_set_fd(sockinfo->ssl, sockinfo->sock);
 	while ((ret = SSL_connect(sockinfo->ssl)) != 1) {
 		err = SSL_get_error(sockinfo->ssl, ret);