Not sending email

Please upgrade to 1.2.2 and post the new debug output (it will have more details).
But afaik WAMP, Gmail and PHP 5.6 have SSL issues.

Thanks for your response.
updated. Here is the result:
Versions:
WordPress: 4.9.1
WordPress MS: No
PHP: 5.6.19
WP Mail SMTP: 1.2.2

Params:
Mailer: gmail
Constants: No
Client ID/Secret: Yes
Auth Code: Yes
Access Token: No

Server:
OpenSSL: Yes
PHP.allow_url_fopen: Yes
PHP.stream_socket_client(): Yes
PHP.fsockopen(): Yes
PHP.curl_version(): Yes
Apache.mod_security: No

Debug:
cURL error 60: SSL certificate problem: unable to get local issuer certificate (see https://curl.haxx.se/libcurl/c/libcurl-errors.html)
cURL error 60: SSL certificate problem: unable to get local issuer certificate (see https://curl.haxx.se/libcurl/c/libcurl-errors.html)
Error while sending via Gmail mailer: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see https://curl.haxx.se/libcurl/c/libcurl-errors.html)
cURL error 60: SSL certificate problem: unable to get local issuer certificate (see https://curl.haxx.se/libcurl/c/libcurl-errors.html)

I just tried with a non-Gmail account and it seems working now. Thanks

@reza_rad,

Glad to hear that!

—

Regarding this error:

SSL certificate problem: unable to get local issuer certificate

That means what it said: you have a misconfigured SSL certificate on a server. You will need to contact your hosting support and ask them to fix that error for you (it’s a server-side issue, I can’t do anything here).

As a temporary solution you can put this code: https://gist.github.com/slaFFik/c1d7d4249f47da7195fb973109952090 – into your child theme functions.php or own new plugin. That might prevent from those errors to appear and SMTP connection to actually work. But I highly discourage doing that.