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Many times you would see emails arriving in your mailbox perfectly but you would not be able to send emails. When you find yourself in similar situation, first thing you should verify is that your email client is configured properly. You can use following email client settings according to your service with AccuWebHosting.

Windows Shared Hosting Customers


Without SSL With SSL
  • Incoming Server: mail.domain.com
  • Outgoing Server: mail.domain.com
  • Username: Full email address
  • Password: Email account password
  • Incoming Port: POP3 110 or IMAP 143
  • Outgoing Mail server (SMTP) Port: 25 or 587
  • SSL: NO
  • SMTP Authentication Required
  • Incoming Server: mail.domain.com
  • Outgoing Server: mail.domain.com
  • Username: Full email address
  • Password: Email account password
  • Incoming Port: POP3 995 or IMAP 993
  • Outgoing Mail server (SMTP) Port: 465
  • SSL: YES
  • SMTP Authentication Required

Linux Shared Hosting Customers


Without SSL With SSL
  • Incoming Server: mail.domain.com
  • Outgoing Server: mail.domain.com
  • Username: Full email address
  • Password: Email account password
  • Incoming Port: POP3 110 or IMAP 143
  • Outgoing Mail server (SMTP) Port: 25, 26 or 587
  • SSL: NO
  • SMTP Authentication Required
  • Incoming Server: mail.domain.com
  • Outgoing Server: mail.domain.com
  • Username: Full email address
  • Password: Email account password
  • Incoming Port: POP3 995 or IMAP 993
  • Outgoing Mail server (SMTP) Port: 465
  • SSL: YES
  • SMTP Authentication Required


VPS Hosting Customers

Without SSL
  • Incoming Server: mail.domain.com
  • Outgoing Server: mail.domain.com
  • Username: Email address
  • Password: Email account password
  • Incoming Port: POP3 110 or IMAP 143
  • Outgoing Mail server (SMTP) Port: 25 or 587
  • SSL: NO
  • SMTP Authentication Required

By default, SSL/TLS would not be configured in Linux (Dovecot) and Windows (SmarterMail) mail servers. You can follow below mentioned tutorials to secure SmarterMail and Dovecot mail server respectively.


ISP Blocking Port 25


When you are unable to send emails, the problem is likely with your Internet service provider also. Your Internet service provider might be blocking outgoing port 25 as a safeguard against their connections being used to send spam. While you attempt you send an email through email client installed in your local computer, it will use port 25 to transmit data to remote email servers. If your ISP is blocking port 25, your email wont't be delivered.

How Do I Determine If Port 25 is Blocked?


To verify whether your ISP blocks port 25 or not, open command prompt (Start >> Run >> cmd + enter) on your local computer and run the following command.

telnet mail.domain.com 25 // Replace your domain name with domain.com. VPS customers replace mail.domain.com with VPS IP address.

If you get a failure message, no response or message similar to following, most probably port 25 block is the issue here.

Trying 192.168.1.1... 
telnet: Unable to connect to remote host: Connection refused

If you receive response similar to this, port 25 is not blocked.

Trying 192.168.1.1... 
Connected to 192.168.1.1.
Escape character is '^]'.
220 hostname.home ESMTP MailEnable Service, Version: 9.00-- ready at 10/09/15 10:31:13

If you receive following error while running telnet command, it indicates that telnet is disabled in your local computer. To enable telnet command, check out an article How to enable telnet command.

'telnet' is not recognized as an internal or external command, operable program or batch file.


Note: It is recommended to use bulk email checker service before starting an email campaign.
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