diff --git a/src/backend/model/diagnostics/ConfigDiagnostics.ts b/src/backend/model/diagnostics/ConfigDiagnostics.ts
index f803763e..caa530f3 100644
--- a/src/backend/model/diagnostics/ConfigDiagnostics.ts
+++ b/src/backend/model/diagnostics/ConfigDiagnostics.ts
@@ -85,7 +85,7 @@ export class ConfigDiagnostics {
   private static async testEmailMessagingConfig(Messaging: MessagingConfig, config: PrivateConfigClass): Promise<void> {
     Logger.debug(LOG_TAG, 'Testing EmailMessaging config');
 
-    if (Messaging.Email.type === EmailMessagingType.sendmail && !Config.Environment.sendMailAvailable) {
+    if (Messaging.Email.type === EmailMessagingType.sendmail && ServerEnvironment.sendMailAvailable === false) {
       throw new Error('sendmail e-mail sending method is not supported as the sendmail application cannot be found in the OS.');
     }
   }
@@ -306,12 +306,12 @@ export class ConfigDiagnostics {
       sendmail: true,
     });
     try {
-      Config.Environment.sendMailAvailable = await transporter.verify();
+      ServerEnvironment.sendMailAvailable = await transporter.verify();
     } catch (e) {
-      Config.Environment.sendMailAvailable = false;
+      ServerEnvironment.sendMailAvailable = false;
     }
-    ServerEnvironment.sendMailAvailable = Config.Environment.sendMailAvailable;
-    if (!Config.Environment.sendMailAvailable) {
+    Config.Environment.sendMailAvailable = ServerEnvironment.sendMailAvailable;
+    if (!ServerEnvironment.sendMailAvailable) {
       Config.Messaging.Email.type = EmailMessagingType.SMTP;
       Logger.info(LOG_TAG, 'Sendmail is not available on the OS. You will need to use an SMTP server if you wish the app to send mails.');
     }
diff --git a/test/backend/unit/middlewares/admin/SettingsMWs.ts b/test/backend/unit/middlewares/admin/SettingsMWs.ts
index 0abc961a..d0dbc658 100644
--- a/test/backend/unit/middlewares/admin/SettingsMWs.ts
+++ b/test/backend/unit/middlewares/admin/SettingsMWs.ts
@@ -55,7 +55,7 @@ describe('Settings middleware', () => {
   it('should save enforced users settings', (done: (err?: any) => void) => {
 
     ServerEnvironment.sendMailAvailable = false;
-    Config.Environment.sendMailAvailable = false
+    Config.Environment.sendMailAvailable = false;
     Config.Messaging.Email.type = EmailMessagingType.sendmail;
     const req: any = {
       session: {},
@@ -80,9 +80,14 @@ describe('Settings middleware', () => {
         expect(Config.Users.enforcedUsers[0].name).to.be.equal('Apple');
         expect(Config.Users.enforcedUsers.length).to.be.equal(1);
         Config.original().then((cfg) => {
-          expect(cfg.Users.enforcedUsers.length).to.be.equal(1);
-          expect(cfg.Users.enforcedUsers[0].name).to.be.equal('Apple');
-          done();
+          try {
+            expect(cfg.Users.enforcedUsers.length).to.be.equal(1);
+            expect(cfg.Users.enforcedUsers[0].name).to.be.equal('Apple');
+            done();
+          } catch (err) {
+            console.error(err);
+            done(err);
+          }
         }).catch(done);
       } catch (err) {
         console.error(err);