fix Swift_TransportException error in laravel 5.4

I am trying to make reset Password in laravel 5.4. In env file I have changed

MAIL_DRIVER=smtp
MAIL_HOST=smtp.mailtrap.io
MAIL_PORT=2525
MAIL_USERNAME=*****************
MAIL_PASSWORD=****************
MAIL_ENCRYPTION=null

Error shows

Swift_TransportException Connection could not be established with host mailtrap.io [A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

10060]

How can I fix it? I use mailtrap.io Thanks in advance

via Chebli Mohamed