Question: I'm looking for an email client that can handle multiple accounts and has a customizable interface.

If you want an email client that can handle multiple accounts and has a customizable interface, Mailbird could be the way to go. The Windows-only email client supports multiple email services like Gmail and Outlook and has a customizable workspace. Its AI-powered email composition, message snoozing and integration with services like Google Calendar make it a good all-purpose option. Mailbird has a range of pricing options, including a free version and premium tiers.

Another option worth considering is BlueMail. The cross-platform app supports multiple email services and lets you manage an unlimited number of mail accounts. It's got features like instant push notifications, unified folders and calendar integration. BlueMail also has a Generative Email AI (GemAI) based on ChatGPT that can summarize and draft emails more quickly. The app is available for Windows, Mac, Linux, Android and iOS, and has free and premium versions.

If you want to go even deeper into the AI world, SaneBox is a good option. The email management system uses machine learning to categorize incoming emails into folders you can prioritize, so you can focus on the most important messages. It also has features like BlackHole to block spammers, Snooze to delay emails and Daily Digest to summarize non-priority emails. SaneBox works with Gmail, Microsoft 365 and Apple iCloud, and has a range of pricing options.

Last, Shortwave has a number of features to help you get a handle on your inbox. Its AI tools include predictive autocomplete suggestions, instant email summaries and customizable tabs for important emails. Shortwave also supports multiple email services and has a range of pricing options, so it's a good option if you have multiple email accounts.