Perhaps the name of the smart host is wrong (a not uncommon problem when ... respond to a request to connect and send messages is: “421 4.2.1 Unable to ...
19.10.2018 · Our experts have had an average response time of 12.49 minutes in November 2021 to fix urgent issues. ... SMTP Error: Could not connect to SMTP host. ... Many ISPs also block the default SMTP port (25), to avoid spamming attempts.
SMTP Status Codes ... 421 can be caused by many things but generally indicates that the mail server which returns this status code is currently unavailable but ...
If you're unable to connect to the SMTP host from the JIRA host, it may indicate a problem with the network. Please check this with your hosting provider or System Administrator.
20.06.2014 · 421 can be caused by many things but generally indicates that the mail server which returns this status code is currently unavailable but may be available later.
Fix Common Gmail Pop3 Errors · Repeatedly prompted for your username and password or 'invalid credentials' error. · The connection to the server has failed. · The ...
Could not open connection to the host, on port 25: Connect Failed. how to send mail using gmail server Building a Better World in your Backyard by Paul Wheaton and Shawn Klassen-Koop
Sometimes wrong SMTP configuration can be the reason for the Outlook error 421. Hence, changing the SMTP port can fix the problem. Open the Outlook app, select the "File" menu. Now, tap "Account Settings" Now, choose your account and select "Change" Look for the "Outgoing mail server (SMTP)" and key in the address provided by the web host.
16.01.2012 · javax.mail.MessagingException: Could not connect to SMTP host: smtp.gmail.com, port: 25; I tried to send an email through a jsp page but it shows the following error: javax.mail.MessagingException: Could not connect to SMTP host: www.gmail.com, port: 25, response: 421. This is the code I'm using to send the email:
17.04.2012 · I am running single threaded java program to sends emails out.It sends approx 250 emails per minute. Emails are sent out successfully but after some hours I always get messaging exception "Could not connect to smtp host:< ip >,port : 25,response :421". Once this comes it never stopped coming.I had to restart app server to get if of it.
20.01.2015 · Failed message 1: javax.mail.MessagingException: Could not connect to SMTP host: smtp.9business.fr, port: 25, response: 421] with root cause even if I'm using port 465 why is he pointing to port 25 ?
15.12.2017 · Some users have reported receiving the “server responded: 421 cannot connect to SMT / SMTP server” error when trying to send an email in Outlook. Often times the error appears due to incorrect settings for the SMTP/ /SMT server, but there are a few other causes that will trigger this Outlook behavior.