Log the message ID's from the messages that have been dispatched to the transport

LogDispatchedMessageIdBehavior.cs

using System;
using System.Threading.Tasks;
using NServiceBus.Logging;
using NServiceBus.Pipeline;

/// <code>
/// endpointConfiguration.Pipeline.Register(behavior: new LogDispatchedMessageIdBehavior(), description: LogDispatchedMessageIdBehavior.Description);
/// </code>
class LogDispatchedMessageIdBehavior : Behavior<IBatchDispatchContext>
{
    public const string Description = "Log the message ID of the message that has been dispatched.";
    static readonly ILog Log = LogManager.GetLogger(nameof(LogDispatchedMessageIdBehavior));

    public override Task Invoke(IBatchDispatchContext context, Func<Task> next)
    {
        var messageIds = string.Join(", ", context.Operations.Select(x => x.Message.MessageId));
        Log.InfoFormat("Dispatching messages {0}", messageIds);
        return next();
    }
}