I am using the JakartaMail API in my Spring Boot application and I have already created a fetch profile and I am able to get the message content printed out on the command line. However, I need some help in retrieving the email content from the IMAP server and storing it into an array so my client can properly display it. Furthermore, I am only getting envelope items, i.e. from, to subject, etc., but my request are not working and my requests are always timed out.

I need help in understanding a flow to properly retrieve the email and the envelope content to then send back to the client.

Here is detail run down of the code I have thus far we will start with the email service that will fetch the email content:

@Async
public CompletableFuture<List<EmailResponseDto>> fetchEmails() {
    List<EmailResponseDto> emailResponseDtoList = new ArrayList<>();
    try {
        Properties prop = new Properties();
        prop.put("mail.store.protocol", "imaps");
        prop.put("mail.imaps.host", "imap.gmail.com");
        prop.put("mail.imaps.port", "993");
        prop.put("mail.imaps.ssl.enable", "true");
        prop.put("mail.imaps.ssl.protocols", "TLSv1.2");
        prop.put("mail.imaps.ssl.trust", "*");

        Session emailSession = Session.getInstance(prop, new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("username", "password");
            }
        });

        FetchProfile profile = new FetchProfile();
        profile.add(FetchProfile.Item.ENVELOPE);

        Store store = emailSession.getStore("imaps");
        store.connect("username", "password");

        Folder emailFolder = store.getFolder("INBOX");
        emailFolder.open(Folder.READ_ONLY);

        emailFolder.fetch(emailFolder.getMessages(), profile);

        for (Message message : emailFolder.getMessages()) {
            EmailResponseDto emailResponseDto = new EmailResponseDto();
            emailResponseDto.setSubject(message.getSubject());
            emailResponseDto.setFrom(message.getFrom()[0].toString());
            emailResponseDto.setSentDate(message.getSentDate());
            emailResponseDtoList.add(emailResponseDto);
        }

        emailFolder.close(false);
        store.close();

    } catch (MessagingException e) {
        e.printStackTrace();
    }
    return CompletableFuture.completedFuture(emailResponseDtoList);
}

I am able to get a response back, but I get a 401 response, and my API client tells me “No Body returned for Response”

I am using an async function because I understand I will get a ton of emails. However, even if I limit the amount, I am not able to get a response back. I am wondering is my implementation or logic, correct? Should I instead be writing the email content to a file instead?