Unfortunately mailgo is not actively maintained anymore. I'm sorry for this but I personally don't have time to maintain it... I hope someone will take over the project.

Transform all your mailto and tel link in a beautiful modal with more possibilities! Open directly Gmail, Outlook and Yahoo for emails; Telegram, WhatsApp or Skype for phone numbers.

https://www.gatsbyjs.com/plugins/gatsby-plugin-mailgo/

https://wordpress.org/plugins/mailgo/