Trouble sending emails using Action mailer in rails 7

Question

I am having trouble sending emails via action mailer in rails 7 app. Now If I configure my action mailer using gmail, it works fine and sends emails as expected. The setting is following.

config.action_mailer.delivery_method = :smtp
  config.action_mailer.default_url_options = { host: 'localhost', port: '3000' }
  config.action_mailer.perform_deliveries = true
  config.action_mailer.raise_delivery_errors = true
  config.action_mailer.default charset: 'utf-8'

 config.action_mailer.smtp_settings = {
     address: 'smtp.gmail.com',
     port: 587,
     user_name: Rails.application.credentials.dig(:Email, :username),
     password:  Rails.application.credentials.dig(:Email, :password),
     authentication: 'plain'
   }

If I change this to other service than gmail, I do not receive emails in my inbox. I do see in logs that it sends email but it never arrives in the destination inbox. The setting is following

config.action_mailer.delivery_method = :smtp
  config.action_mailer.default_url_options = { host: 'localhost', port: '3000' }
  config.action_mailer.perform_deliveries = true
  config.action_mailer.raise_delivery_errors = true
  config.action_mailer.default charset: 'utf-8'

  config.action_mailer.smtp_settings = {
  address: 'mail.punjab.gov.pk',
  port: 25,
  user_name: Rails.application.credentials.dig(:Email, :username),
  password:  Rails.application.credentials.dig(:Email, :password),
  authentication: 'plain'
}