code: protected function resendActivationMail(MemberModel $objMember)
  	{
  		if ($objMember->disable == '')
  		{
  			return;
  		}
  
  		$this->strTemplate = 'mod_message';
  		$this->Template = new FrontendTemplate($this->strTemplate);
  
  		/** @var OptIn $optIn */
  		$optIn = System::getContainer()->get('contao.opt-in');
  		$optInToken = null;
  		$models = OptInModel::findByRelatedTableAndIds('tl_member', array($objMember->id));
  
  		foreach ($models as $model)
  		{
  			// Look for a valid, unconfirmed token
  			if (($token = $optIn->find($model->token)) && $token->isValid() && !$token->isConfirmed())
  			{
  				$optInToken = $token;
  				break;
  			}
  		}
  
  		if ($optInToken === null)
  		{
  			return;
  		}
  
  		$optInToken->send();
  
  		// Confirm activation
  		$this->Template->type = 'confirm';
  		$this->Template->message = $GLOBALS['TL_LANG']['MSC']['resendActivation'];
  	}
docs: Re-send the activation mail
  
  @param MemberModel $objMember