diff --git a/application/Espo/Resources/layouts/EmailAccount/detail.json b/application/Espo/Resources/layouts/EmailAccount/detail.json
index faaef4e10d..bf98da5057 100644
--- a/application/Espo/Resources/layouts/EmailAccount/detail.json
+++ b/application/Espo/Resources/layouts/EmailAccount/detail.json
@@ -8,14 +8,14 @@
             ],
             [
                 {"name":"name"},
-                {"name":"fetchSince"}
+                false
             ]
         ]
     },
     {
         "label":"IMAP",
         "rows":[
-            [{"name": "useImap"}, false],
+            [{"name": "useImap"}, {"name":"fetchSince"}],
             [
                 {"name":"host"},{"name":"ssl"}
             ],
diff --git a/application/Espo/Resources/layouts/InboundEmail/detail.json b/application/Espo/Resources/layouts/InboundEmail/detail.json
index 9127a0a004..19269ee87d 100644
--- a/application/Espo/Resources/layouts/InboundEmail/detail.json
+++ b/application/Espo/Resources/layouts/InboundEmail/detail.json
@@ -12,7 +12,7 @@
             ],
             [
                 {"name":"teams"},
-                {"name":"fetchSince"}
+                false
             ],
             [
                 {"name":"addAllTeamUsers"},
@@ -23,7 +23,7 @@
     {
         "label": "IMAP",
         "rows": [
-            [{"name": "useImap"}, false],
+            [{"name": "useImap"}, {"name":"fetchSince"}],
             [
                 {"name":"host"},{"name":"ssl"}
             ],
diff --git a/application/Espo/Resources/metadata/clientDefs/EmailAccount.json b/application/Espo/Resources/metadata/clientDefs/EmailAccount.json
index b189661ff0..853be96365 100644
--- a/application/Espo/Resources/metadata/clientDefs/EmailAccount.json
+++ b/application/Espo/Resources/metadata/clientDefs/EmailAccount.json
@@ -56,6 +56,32 @@
                         }
                     ]
                 }
+            },
+            "fetchSince": {
+                "visible": {
+                    "conditionGroup": [
+                        {
+                            "type": "isTrue",
+                            "attribute": "useImap"
+                        }
+                    ]
+                },
+                "readOnly": {
+                    "conditionGroup": [
+                        {
+                            "type": "isNotEmpty",
+                            "attribute": "fetchData"
+                        }
+                    ]
+                },
+                "required": {
+                    "conditionGroup": [
+                        {
+                            "type": "isTrue",
+                            "attribute": "useImap"
+                        }
+                    ]
+                }
             }
         }
     },
diff --git a/application/Espo/Resources/metadata/clientDefs/InboundEmail.json b/application/Espo/Resources/metadata/clientDefs/InboundEmail.json
index 3e454825ca..eb310c3ee4 100644
--- a/application/Espo/Resources/metadata/clientDefs/InboundEmail.json
+++ b/application/Espo/Resources/metadata/clientDefs/InboundEmail.json
@@ -49,6 +49,32 @@
                         }
                     ]
                 }
+            },
+            "fetchSince": {
+                "visible": {
+                    "conditionGroup": [
+                        {
+                            "type": "isTrue",
+                            "attribute": "useImap"
+                        }
+                    ]
+                },
+                "readOnly": {
+                    "conditionGroup": [
+                        {
+                            "type": "isNotEmpty",
+                            "attribute": "fetchData"
+                        }
+                    ]
+                },
+                "required": {
+                    "conditionGroup": [
+                        {
+                            "type": "isTrue",
+                            "attribute": "useImap"
+                        }
+                    ]
+                }
             }
         }
     },
diff --git a/application/Espo/Resources/metadata/entityDefs/EmailAccount.json b/application/Espo/Resources/metadata/entityDefs/EmailAccount.json
index 6eea6a548a..f13c0b5100 100644
--- a/application/Espo/Resources/metadata/entityDefs/EmailAccount.json
+++ b/application/Espo/Resources/metadata/entityDefs/EmailAccount.json
@@ -56,8 +56,7 @@
             "type": "bool"
         },
         "fetchSince": {
-            "type": "date",
-            "required": true
+            "type": "date"
         },
         "fetchData": {
             "type": "jsonObject",
diff --git a/application/Espo/Resources/metadata/entityDefs/InboundEmail.json b/application/Espo/Resources/metadata/entityDefs/InboundEmail.json
index 9f37a3d61b..393e06867c 100644
--- a/application/Espo/Resources/metadata/entityDefs/InboundEmail.json
+++ b/application/Espo/Resources/metadata/entityDefs/InboundEmail.json
@@ -44,8 +44,7 @@
             "tooltip": true
         },
         "fetchSince": {
-            "type": "date",
-            "required": true
+            "type": "date"
         },
         "fetchData": {
             "type": "jsonObject",
diff --git a/application/Espo/Services/EmailAccount.php b/application/Espo/Services/EmailAccount.php
index d8716dab2f..418fc9788f 100644
--- a/application/Espo/Services/EmailAccount.php
+++ b/application/Espo/Services/EmailAccount.php
@@ -29,11 +29,13 @@
 
 namespace Espo\Services;
 
-use \Espo\ORM\Entity;
+use Espo\ORM\Entity;
 
-use \Espo\Core\Exceptions\Error;
-use \Espo\Core\Exceptions\Forbidden;
-use \Zend\Mail\Storage;
+use Espo\Core\Exceptions\Error;
+use Espo\Core\Exceptions\Forbidden;
+use Espo\Core\Exceptions\BadRequest;
+
+use Zend\Mail\Storage;
 
 class EmailAccount extends Record
 {
@@ -64,6 +66,17 @@ class EmailAccount extends Record
         }
     }
 
+    public function processValidation(Entity $entity, $data)
+    {
+        parent::processValidation($entity, $data);
+
+        if ($entity->get('useImap')) {
+            if (!$entity->get('fetchSince')) {
+                throw new BadRequest("EmailAccount validation: fetchSince is required.");
+            }
+        }
+    }
+
     public function getFolders($params)
     {
         $userId = $params['userId'] ?? null;
diff --git a/application/Espo/Services/InboundEmail.php b/application/Espo/Services/InboundEmail.php
index e9176a300d..b9d50ca4ed 100644
--- a/application/Espo/Services/InboundEmail.php
+++ b/application/Espo/Services/InboundEmail.php
@@ -35,6 +35,7 @@ use Zend\Mail\Storage;
 
 use Espo\Core\Exceptions\Error;
 use Espo\Core\Exceptions\Forbidden;
+use Espo\Core\Exceptions\BadRequest;
 
 class InboundEmail extends \Espo\Services\Record
 {
@@ -74,6 +75,17 @@ class InboundEmail extends \Espo\Services\Record
         }
     }
 
+    public function processValidation(Entity $entity, $data)
+    {
+        parent::processValidation($entity, $data);
+
+        if ($entity->get('useImap')) {
+            if (!$entity->get('fetchSince')) {
+                throw new BadRequest("EmailAccount validation: fetchSince is required.");
+            }
+        }
+    }
+
     public function getFolders($params)
     {
         if (!empty($params['id'])) {