[MM-54594] Adding new global relay type (#24672)

* adding new global relay type, custom

server/i18n/en.json

@@ -8848,7 +8848,11 @@
   },
   {
     "id": "model.config.is_valid.message_export.global_relay.customer_type.app_error",
-    "translation": "Message export GlobalRelaySettings.CustomerType must be set to one of either 'A9' or 'A10'."
+    "translation": "Message export GlobalRelaySettings.CustomerType must be set to one of either 'A9', 'A10' or 'CUSTOM."
+  },
+  {
+    "id": "model.config.is_valid.message_export.global_relay.customer_type_custom.app_error",
+    "translation": "If GlobalRelaySettings.CustomerType is 'CUSTOM', then GlobalRelaySettings.CustomSMTPServerName and GlobalRelaySettings.CustomSMTPPort must be set."
   },
   {
     "id": "model.config.is_valid.message_export.global_relay.email_address.app_error",

server/public/model/config.go

@@ -226,6 +226,7 @@ const (
 	ComplianceExportTypeGlobalrelayZip = "globalrelay-zip"
 	GlobalrelayCustomerTypeA9          = "A9"
 	GlobalrelayCustomerTypeA10         = "A10"
+	GlobalrelayCustomerTypeCustom      = "CUSTOM"
 
 	ClientSideCertCheckPrimaryAuth   = "primary"
 	ClientSideCertCheckSecondaryAuth = "secondary"
@@ -3108,11 +3109,13 @@ func (s *PluginSettings) SetDefaults(ls LogSettings) {
 }
 
 type GlobalRelayMessageExportSettings struct {
-	CustomerType      *string `access:"compliance_compliance_export"` // must be either A9 or A10, dictates SMTP server url
-	SMTPUsername      *string `access:"compliance_compliance_export"`
-	SMTPPassword      *string `access:"compliance_compliance_export"`
-	EmailAddress      *string `access:"compliance_compliance_export"` // the address to send messages to
-	SMTPServerTimeout *int    `access:"compliance_compliance_export"`
+	CustomerType         *string `access:"compliance_compliance_export"` // must be either A9, A10 or CUSTOM, dictates SMTP server url
+	SMTPUsername         *string `access:"compliance_compliance_export"`
+	SMTPPassword         *string `access:"compliance_compliance_export"`
+	EmailAddress         *string `access:"compliance_compliance_export"` // the address to send messages to
+	SMTPServerTimeout    *int    `access:"compliance_compliance_export"`
+	CustomSMTPServerName *string `access:"compliance_compliance_export"`
+	CustomSMTPPort       *string `access:"compliance_compliance_export"`
 }
 
 func (s *GlobalRelayMessageExportSettings) SetDefaults() {
@@ -3131,6 +3134,12 @@ func (s *GlobalRelayMessageExportSettings) SetDefaults() {
 	if s.SMTPServerTimeout == nil || *s.SMTPServerTimeout == 0 {
 		s.SMTPServerTimeout = NewInt(1800)
 	}
+	if s.CustomSMTPServerName == nil {
+		s.CustomSMTPServerName = NewString("")
+	}
+	if s.CustomSMTPPort == nil {
+		s.CustomSMTPPort = NewString("25")
+	}
 }
 
 type MessageExportSettings struct {
@@ -4105,8 +4114,10 @@ func (s *MessageExportSettings) isValid() *AppError {
 		if *s.ExportFormat == ComplianceExportTypeGlobalrelay {
 			if s.GlobalRelaySettings == nil {
 				return NewAppError("Config.IsValid", "model.config.is_valid.message_export.global_relay.config_missing.app_error", nil, "", http.StatusBadRequest)
-			} else if s.GlobalRelaySettings.CustomerType == nil || (*s.GlobalRelaySettings.CustomerType != GlobalrelayCustomerTypeA9 && *s.GlobalRelaySettings.CustomerType != GlobalrelayCustomerTypeA10) {
+			} else if s.GlobalRelaySettings.CustomerType == nil || (*s.GlobalRelaySettings.CustomerType != GlobalrelayCustomerTypeA9 && *s.GlobalRelaySettings.CustomerType != GlobalrelayCustomerTypeA10 && *s.GlobalRelaySettings.CustomerType != GlobalrelayCustomerTypeCustom) {
 				return NewAppError("Config.IsValid", "model.config.is_valid.message_export.global_relay.customer_type.app_error", nil, "", http.StatusBadRequest)
+			} else if *s.GlobalRelaySettings.CustomerType == GlobalrelayCustomerTypeCustom && ((s.GlobalRelaySettings.CustomSMTPServerName == nil || *s.GlobalRelaySettings.CustomSMTPServerName == "") || (s.GlobalRelaySettings.CustomSMTPPort == nil || *s.GlobalRelaySettings.CustomSMTPPort == "")) {
+				return NewAppError("Config.IsValid", "model.config.is_valid.message_export.global_relay.customer_type_custom.app_error", nil, "", http.StatusBadRequest)
 			} else if s.GlobalRelaySettings.EmailAddress == nil || !strings.Contains(*s.GlobalRelaySettings.EmailAddress, "@") {
 				// validating email addresses is hard - just make sure it contains an '@' sign
 				// see https://stackoverflow.com/questions/201323/using-a-regular-expression-to-validate-an-email-address