One of the client reported that they are unable to send email using  WP Mail SMTP Plugin while trying to use the in house exchange server as relay on port 25, they were getting the following error

ERROR: Failed to connect to server: Connection timed out (110)

Error : Connection refused : 111

We were using our internal SMTP (exchange 2010) server to relay the email, we validated that the exchange server is fine and in state to send or receive emails via port 25 . validated the same by configuring an outlook from outside the network.

Still the wordpress developer wasn’t able to reach to the server to relay its emails.


1) We made the exchange server an open relay but still wordpress was unable to connect

2) I logged into  wordpress console and configure it with gmail credentials used following settings for Gmail

Mailer: SMTP
SMTP Host:
SMTP Port: 465
Encryption: SSL
Authentication: Yes
Username: your full gmail address
Password: your mail password

Referred this link for settings : Link

3) This also didnt work with error 110

4) I decided to replicate the issue on my wordpress installation, so that I can get better control

5) Installed the plugin on my install and used the same Gmail settings to relay, found it working good 🙂

6) Tried the exchange relay settings and it failed with error 110

ERROR: Failed to connect to server: Connection timed out (110)

7) I was sure its not our exchange server issue, so reached out to my host Site Ground for support

8) Provided them the require settings and they tested and found that they were blocking port 25 outbound communication

9) They made the firewall change and the SMTP mail started to flow as smooth as silk…Hooray 🙂


If you are getting this error 110,100 (connection time out or connection refused), please get in touch with your word press host to validate that the SMTP port which you are trying to connect to is allowed for outbound communication  on their firewall


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An automobile enthusiast at heart and computer geek by profession, started my Career with MS in 2005.Left Jobs and started Pledge Technologies (the parent company to Grishbi) back in 2009.We have been providing IT consulting to various Small and Medium businesses across US and UK since then.Our company specialises in Microsoft Server technologies like AD, Exchange, the rest and with numerous Office 365 migrations under our belt, we quite an expert with that too. Whatever we learn in our day to day life, we share it back on Grishbi as a Thank for all the love and support our customers have given us.
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