diff --git a/src/Postmark/IPostmarkClient.cs b/src/Postmark/IPostmarkClient.cs
new file mode 100644
index 0000000..c7091e9
--- /dev/null
+++ b/src/Postmark/IPostmarkClient.cs
@@ -0,0 +1,76 @@
+using Postmark.Model.MessageStreams;
+using Postmark.Model.Suppressions;
+using PostmarkDotNet.Model;
+using PostmarkDotNet.Model.Webhooks;
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace PostmarkDotNet
+{
+    interface IPostmarkClient
+    {
+        Task<PostmarkBounceActivation> ActivateBounceAsync(long bounceId);
+        Task<PostmarkMessageStreamArchivalConfirmation> ArchiveMessageStream(string id);
+        Task<PostmarkResponse> BypassBlockedInboundMessage(string messageid);
+        Task<PostmarkInboundRuleTriggerInfo> CreateInboundRuleTriggerAsync(string rule);
+        Task<PostmarkMessageStream> CreateMessageStream(string id, MessageStreamType type, string name, string description = null);
+        Task<PostmarkBulkSuppressionResult> CreateSuppressions(IEnumerable<PostmarkSuppressionChangeRequest> suppressionChanges, string messageStream = "outbound");
+        Task<BasicTemplateInformation> CreateTemplateAsync(string name, string subject, string htmlBody = null, string textBody = null, string alias = null, TemplateType templateType = TemplateType.Standard, string layoutTemplate = null);
+        Task<WebhookConfiguration> CreateWebhookConfigurationAsync(string url, string messageStream = null, HttpAuth httpAuth = null, IEnumerable<HttpHeader> httpHeaders = null, WebhookConfigurationTriggers triggers = null);
+        Task<PostmarkResponse> DeleteInboundRuleTrigger(int triggerId);
+        Task<PostmarkBulkReactivationResult> DeleteSuppressions(IEnumerable<PostmarkSuppressionChangeRequest> suppressionChanges, string messageStream = "outbound");
+        Task<PostmarkResponse> DeleteTemplateAsync(long templateId);
+        Task<PostmarkResponse> DeleteTemplateAsync(string templateAlias);
+        Task<PostmarkResponse> DeleteWebhookConfigurationAsync(long configurationId);
+        Task<PostmarkMessageStream> EditMessageStream(string id, string name = null, string description = null);
+        Task<PostmarkServer> EditServerAsync(string name = null, string color = null, bool? rawEmailEnabled = null, bool? smtpApiActivated = null, string inboundHookUrl = null, string bounceHookUrl = null, string openHookUrl = null, bool? postFirstOpenOnly = null, bool? trackOpens = null, string inboundDomain = null, int? inboundSpamThreshold = null, LinkTrackingOptions? trackLinks = null, string clickHookUrl = null, string deliveryHookUrl = null);
+        Task<BasicTemplateInformation> EditTemplateAsync(long templateId, string name = null, string subject = null, string htmlBody = null, string textBody = null, string alias = null, string layoutTemplate = null);
+        Task<BasicTemplateInformation> EditTemplateAsync(string alias, string name = null, string subject = null, string htmlBody = null, string textBody = null, string layoutTemplate = null);
+        Task<WebhookConfiguration> EditWebhookConfigurationAsync(long configurationId, string url, HttpAuth httpAuth = null, IEnumerable<HttpHeader> httpHeaders = null, WebhookConfigurationTriggers triggers = null);
+        Task<PostmarkInboundRuleTriggerList> GetAllInboundRuleTriggers(int offset = 0, int count = 100);
+        Task<PostmarkBounce> GetBounceAsync(long bounceId);
+        Task<PostmarkBounceDump> GetBounceDumpAsync(long bounceId);
+        Task<PostmarkBounces> GetBouncesAsync(int offset = 0, int count = 100, PostmarkBounceType? type = null, bool? inactive = null, string emailFilter = null, string tag = null, string messageID = null, string fromDate = null, string toDate = null);
+        Task<IEnumerable<string>> GetBounceTagsAsync();
+        Task<PostmarkClicksList> GetClickEventsForMessageAsync(string messageId, int offset = 0, int count = 100);
+        Task<PostmarkClicksList> GetClickEventsForMessagesAsync(int offset = 0, int count = 100, string recipient = null, string tag = null, string clientName = null, string clientCompany = null, string clientFamily = null, string operatingSystemName = null, string operatingSystemFamily = null, string operatingSystemCompany = null, string platform = null, string country = null, string region = null, string city = null);
+        Task<PostmarkDeliveryStats> GetDeliveryStatsAsync();
+        Task<InboundMessageDetail> GetInboundMessageDetailsAsync(string messageID);
+        Task<PostmarkInboundMessageList> GetInboundMessagesAsync(int offset = 0, int count = 100, string recipient = null, string fromemail = null, string subject = null, string mailboxhash = null, InboundMessageStatus? status = InboundMessageStatus.Processed, string toDate = null, string fromDate = null);
+        Task<PostmarkMessageStream> GetMessageStream(string id);
+        Task<PostmarkOpensList> GetOpenEventsForMessageAsync(string messageId, int offset = 0, int count = 100);
+        Task<PostmarkOpensList> GetOpenEventsForMessagesAsync(int offset = 0, int count = 100, string recipient = null, string tag = null, string clientName = null, string clientCompany = null, string clientFamily = null, string operatingSystemName = null, string operatingSystemFamily = null, string operatingSystemCompany = null, string platform = null, string country = null, string region = null, string city = null);
+        Task<PostmarkOutboundBounceStats> GetOutboundBounceCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundClientStats> GetOutboundClientUsageCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<OutboundMessageDetail> GetOutboundMessageDetailsAsync(string messageID);
+        Task<MessageDump> GetOutboundMessageDumpAsync(string messageID);
+        Task<PostmarkOutboundMessageList> GetOutboundMessagesAsync(int offset = 0, int count = 100, string recipient = null, string fromemail = null, string tag = null, string subject = null, OutboundMessageStatus status = OutboundMessageStatus.Sent, string toDate = null, string fromDate = null, IDictionary<string, string> metadata = null);
+        Task<PostmarkOutboundOpenStats> GetOutboundOpenCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundOverviewStats> GetOutboundOverviewStatsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundPlatformStats> GetOutboundPlatformCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundReadStats> GetOutboundReadtimeStatsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundSentStats> GetOutboundSentCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundSpamComplaintStats> GetOutboundSpamComplaintCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkOutboundTrackedStats> GetOutboundTrackingCountsAsync(string tag = null, DateTime? fromDate = null, DateTime? toDate = null);
+        Task<PostmarkServer> GetServerAsync();
+        Task<PostmarkTemplate> GetTemplateAsync(string alias);
+        Task<PostmarkTemplate> GetTemplateAsync(long templateId);
+        Task<PostmarkTemplateListingResponse> GetTemplatesAsync(int offset = 0, int count = 100, TemplateTypeFilter templateType = TemplateTypeFilter.All, string layoutTemplate = null);
+        Task<WebhookConfiguration> GetWebhookConfigurationAsync(long configurationId);
+        Task<WebhookConfigurationListingResponse> GetWebhookConfigurationsAsync(string messageStream = null);
+        Task<PostmarkMessageStreamListing> ListMessageStreams(MessageStreamTypeFilter messageStreamType = MessageStreamTypeFilter.All, bool includeArchivedStreams = false);
+        Task<PostmarkSuppressionListing> ListSuppressions(PostmarkSuppressionQuery query, string messageStream = "outbound");
+        Task<PostmarkResponse> RetryInboundHookForMessage(string messageId);
+        Task<IEnumerable<PostmarkResponse>> SendEmailsWithTemplateAsync(params TemplatedPostmarkMessage[] messages);
+        Task<PostmarkResponse> SendEmailWithTemplateAsync<T>(long templateId, T templateModel, string to, string from, bool? inlineCss = null, string cc = null, string bcc = null, string replyTo = null, bool? trackOpens = null, IDictionary<string, string> headers = null, IDictionary<string, string> metadata = null, string messageStream = null, params PostmarkMessageAttachment[] attachments);
+        Task<PostmarkResponse> SendEmailWithTemplateAsync<T>(string templateAlias, T templateModel, string to, string from, bool? inlineCss = null, string cc = null, string bcc = null, string replyTo = null, bool? trackOpens = null, IDictionary<string, string> headers = null, IDictionary<string, string> metadata = null, string messageStream = null, params PostmarkMessageAttachment[] attachments);
+        Task<PostmarkResponse> SendEmailWithTemplateAsync(TemplatedPostmarkMessage emailToSend);
+        Task<PostmarkResponse> SendMessageAsync(TemplatedPostmarkMessage emailToSend);
+        Task<PostmarkResponse> SendMessageAsync(PostmarkMessage message);
+        Task<IEnumerable<PostmarkResponse>> SendMessagesAsync(params TemplatedPostmarkMessage[] messages);
+        Task<IEnumerable<PostmarkResponse>> SendMessagesAsync(params PostmarkMessage[] messages);
+        Task<PostmarkMessageStream> UnArchiveMessageStream(string id);
+        Task<TemplateValidationResponse> ValidateTemplateAsync<T>(string subject = null, string htmlBody = null, string textBody = null, T testRenderModel = default, bool inlineCssForHtmlTestRender = true, TemplateType templateType = TemplateType.Standard, string layoutTemplate = null);
+    }
+}
diff --git a/src/Postmark/PostmarkClient.cs b/src/Postmark/PostmarkClient.cs
index 8004c3f..02a5a54 100644
--- a/src/Postmark/PostmarkClient.cs
+++ b/src/Postmark/PostmarkClient.cs
@@ -18,7 +18,7 @@ namespace PostmarkDotNet
     /// <remarks>
     /// Make sure to include "using PostmarkDotNet;" in your class file, which will include extension methods on the base client.
     /// </remarks>
-    public class PostmarkClient : PostmarkClientBase
+    public class PostmarkClient : PostmarkClientBase, IPostmarkClient
     {
         /// <summary>
         /// The authorization header required, in this case, "X-Postmark-Server-Token"