diff --git a/BTCPayServer.Tests/UnitTest1.cs b/BTCPayServer.Tests/UnitTest1.cs
index b835c5603..152207f78 100644
--- a/BTCPayServer.Tests/UnitTest1.cs
+++ b/BTCPayServer.Tests/UnitTest1.cs
@@ -676,10 +676,10 @@ namespace BTCPayServer.Tests
                 response = await client.GetAsync("http://explorerzydxu5ecjrkwceayqybizmpjjznk5izmitf2modhcusuqlid.onion/");
                 response.EnsureSuccessStatusCode();
 
-                TestLogs.LogInformation("Querying an onion address which can't be found should send http 500");
+                TestLogs.LogInformation("Querying an onion address which can't be found");
                 await Assert.ThrowsAsync<HttpRequestException>(() => client.GetAsync("http://dwoduwoi.onion/"));
 
-                TestLogs.LogInformation("Querying valid onion but unreachable should send error 502");
+                TestLogs.LogInformation("Querying valid onion but unreachable");
                 await Assert.ThrowsAsync<HttpRequestException>(() => client.GetAsync("http://nzwsosflsoquxirwb2zikz6uxr3u5n5u73l33umtdx4hq5mzm5dycuqd.onion/"));
             }
         }
diff --git a/BTCPayServer/Services/Mails/EmailSettings.cs b/BTCPayServer/Services/Mails/EmailSettings.cs
index b137231af..8c551f65e 100644
--- a/BTCPayServer/Services/Mails/EmailSettings.cs
+++ b/BTCPayServer/Services/Mails/EmailSettings.cs
@@ -5,6 +5,8 @@ using MailKit.Net.Smtp;
 using MimeKit;
 using System.Threading.Tasks;
 using System.Threading;
+using System.Net.Security;
+using System.Security.Cryptography.X509Certificates;
 
 namespace BTCPayServer.Services.Mails
 {
@@ -77,6 +79,13 @@ namespace BTCPayServer.Services.Mails
             using var connectCancel = new CancellationTokenSource(10000);
             try
             {
+                if (Extensions.IsLocalNetwork(Server))
+                {
+                    client.CheckCertificateRevocation = false;
+#pragma warning disable CA5359 // Do Not Disable Certificate Validation
+                    client.ServerCertificateValidationCallback = (s, c, h, e) => true;
+#pragma warning restore CA5359 // Do Not Disable Certificate Validation
+                }
                 await client.ConnectAsync(Server, Port.Value, MailKit.Security.SecureSocketOptions.Auto, connectCancel.Token);
                 await client.AuthenticateAsync(Login, Password, connectCancel.Token);
             }