StandManager/StandManager.MailProcessor/MailProcessor.cs

using StandManager.Service.Interfaces;

public class MailProcessor
{
    private readonly IManagerService _managerService;

    public MailProcessor(IManagerService managerService)
    {
        _managerService = managerService;
    }

    public async Task Process()
    {
        var list = await _managerService.MailQueueService.RicercaQueryable(x =>
            x.Eliminato == false && x.Sent == false);
        var a = list;
    }
}