SSIS doesn’t come with any component to download the email attachments. The only way is use script task. You can use your own code or third-party libraries. If the business requirement is more complex I would recommend using third-part libraries rather write your own code. Limilabs Mail.dll .NET email component makes your jobs easy, you can read more details here https://www.limilabs.com/mail. You can find similar libraries and use it.
Add references and then add the following libraries based on your requirement
using Limilabs.Client.IMAP;
using Limilabs.Mail;
using Limilabs.Mail.Headers;
Cheers!
Uma
