diff --git a/htdocs/admin/mailing.php b/htdocs/admin/mailing.php
index 921a4a6338c..6e3341dcd8f 100644
--- a/htdocs/admin/mailing.php
+++ b/htdocs/admin/mailing.php
@@ -125,7 +125,7 @@ print '</td></tr>';
 
 print '<tr class="oddeven"><td>';
 print $langs->trans("MailingDelay").'</td><td>';
-print '<input size="32" type="text" name="MAILING_DELAY" value="'.$conf->global->MAILING_DELAY.'">';
+print '<input class="width75" type="text" name="MAILING_DELAY" value="'.$conf->global->MAILING_DELAY.'">';
 print '</td></tr>';
 
 
diff --git a/htdocs/comm/mailing/card.php b/htdocs/comm/mailing/card.php
index e3cb5a9ad97..80692c1384d 100644
--- a/htdocs/comm/mailing/card.php
+++ b/htdocs/comm/mailing/card.php
@@ -346,7 +346,7 @@ if (empty($reshook))
 						    if (!empty($conf->global->MAILING_DELAY))
 						    {
 						    	dol_syslog("Wait a delay of MAILING_DELAY=".$conf->global->MAILING_DELAY);
-                            	sleep($conf->global->MAILING_DELAY);
+                            	usleep((float) $conf->global->MAILING_DELAY * 1000000);
                         	}
 
                         	//test if CHECK READ change statut prospect contact
diff --git a/scripts/emailings/mailing-send.php b/scripts/emailings/mailing-send.php
index bc7efec7dba..0118697e5ec 100755
--- a/scripts/emailings/mailing-send.php
+++ b/scripts/emailings/mailing-send.php
@@ -318,7 +318,7 @@ if ($resql) {
 								}
 
 								if (!empty($conf->global->MAILING_DELAY)) {
-									sleep($conf->global->MAILING_DELAY);
+									usleep((float) $conf->global->MAILING_DELAY * 1000000);
 								}
 							}
 						} else {