MT4 tells me my SMTP credentials are invalid. MT5 tells me they're not.

[TheFlyingDutchman]

Is there some sort of valid reason as to why MT4 (Version 4, Build 1440) has, all of a sudden, decided to continue to tell me that my SMTP credentials are incorrent, despite the fact that

1. they're not,
2. MT5 does not have any issue with my credentials whatsoever? 

There is no reason that I can work out as to why MT4 gets the arse with me when it comes to setting up the email client. I have even written a Python script which pings a test emaIL using the exact same SMTP credentials, all of which send with no issues. 

This is what I have tried so far:

• I have double checked the credentials,
• I have triple checked the credentials,
• I have quadruple checked the credentials,
• I have quintuple checked the credentials,
• I have sextuple checked the credentials,
• I have tried SendGrid,
• I have tried Brevo,
• I have tried MailerSend,
• I have tried Gmail ,
• I have tried using iCloud,
• I have tried each with port 587,
• I have tried each with port 465,
• I have tried each with port 25,
• I have tried each with port 6543213278974521325789541321324 ,
• I have restarted MT4 52,454 times (yes, I counted & in between each settings change),
• I have turned off the "Enable" check box 57,665 times (yup, counted that too),
• I have turned on the "Enable" check box 57,665 times (obviously),
• I have sold my sanity to the highest bidder

Guess what the result is each time:

Mail: login to smtp-relay.brevo.com:587 failed

Mail: login to smtp-relay.brevo.com:465 failed

Mail: login to smtp-relay.brevo.com:25 failed

Mail: login to smtp-relay.brevo.com:587 failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

...failed

As we all know, MT4 has always been an absolute pig when it comes to setting up SMTP credentials, but after a jiggling it about a few times it usually plays ball.

Not this time.

What is the issue with MT4 that MT5 clearly does not seem to have when it comes setting it up SMTP's?

[Sergey Golubev]

TheFlyingDutchman:

Is there some sort of valid reason as to why MT4 (Version 4, Build 1440) has, all of a sudden, decided to continue to tell me that my SMTP credentials are incorrent, despite the fact that

1. they're not,
2. MT5 does not have any issue with my credentials whatsoever? 

There is no reason that I can work out as to why MT4 gets the arse with me when it comes to setting up the email client. I have even written a Python script which pings a test emaIL using the exact same SMTP credentials, all of which send with no issues. 

...

And this is the post of user telling that this possibility is not disappeared -

Forum on trading, automated trading systems and testing trading strategies

SMTP connection fails

Nguyen Tuan Son, 2025.04.04 02:21

I just tried a MT4 Build 1440, 15 Feb 2025 which downloaded from my broker. It still works. Just follow my guideline in the link above.

It is failed if you use Gmail password but it works with app password. See the attached screenshot

More - 

Forum on trading, automated trading systems and testing trading strategies

SMTP connection fails

Nguyen Tuan Son, 2025.04.03 13:23

Please try this guide: https://www.mql5.com/en/blogs/post/759364

[Sergey Golubev]

The discussion thread about this issue -  Problem : email set up in metatrader4
You will know about email providers who disabled this feature for MT4 (MT4 did not disabled it; it was disabled by email providers: google and yahoo for example - they decide to disabled the feature for some reason).