diff --git a/src/services/ai-kurzy/certificate-email.service.js b/src/services/ai-kurzy/certificate-email.service.js
index fcefd46..e4cf9c8 100644
--- a/src/services/ai-kurzy/certificate-email.service.js
+++ b/src/services/ai-kurzy/certificate-email.service.js
@@ -1,5 +1,6 @@
 import fs from 'fs/promises';
 import path from 'path';
+import axios from 'axios';
 import { db } from '../../config/database.js';
 import { prilohy, registracie, ucastnici, kurzy, emailAccounts, userEmailAccounts } from '../../db/schema.js';
 import { eq, and } from 'drizzle-orm';
@@ -152,6 +153,35 @@ V prípade otázok nás neváhajte kontaktovať.
 `.trim();
 };
 
+/**
+ * Upload blob via HTTP POST to JMAP upload endpoint
+ */
+const uploadBlobToJmap = async (jmapConfig, fileBuffer, mimeType) => {
+  const jmapServer = process.env.JMAP_SERVER || 'https://mail.truemail.sk/jmap/';
+  // Truemail upload URL format
+  const uploadUrl = `${jmapServer}upload/${jmapConfig.accountId}/`;
+
+  logger.info(`Nahrávam súbor na JMAP server: ${uploadUrl}`);
+
+  const response = await axios.post(uploadUrl, fileBuffer, {
+    auth: {
+      username: jmapConfig.username,
+      password: jmapConfig.password,
+    },
+    headers: {
+      'Content-Type': mimeType,
+    },
+  });
+
+  if (!response.data?.blobId) {
+    logger.error('Upload nevrátil blobId', response.data);
+    throw new Error('Nepodarilo sa nahrať prílohu na server');
+  }
+
+  logger.info(`Súbor nahraný, blobId: ${response.data.blobId}`);
+  return response.data.blobId;
+};
+
 /**
  * Send email with HTML content and PDF attachment via JMAP
  */
@@ -166,11 +196,14 @@ const sendEmailWithAttachment = async (jmapConfig, to, subject, htmlBody, textBo
     throw new Error('Priečinok Odoslané nebol nájdený');
   }
 
-  // Read attachment file and encode to base64
+  // Read attachment file
   const fileBuffer = await fs.readFile(attachment.path);
-  const base64Content = fileBuffer.toString('base64');
+  const mimeType = attachment.mimeType || 'application/pdf';
 
-  // Create email with attachment
+  // Upload blob via HTTP POST (this is the correct JMAP way)
+  const blobId = await uploadBlobToJmap(jmapConfig, fileBuffer, mimeType);
+
+  // Create email with uploaded blob
   const createResponse = await jmapRequest(jmapConfig, [
     [
       'Email/set',
@@ -181,29 +214,36 @@ const sendEmailWithAttachment = async (jmapConfig, to, subject, htmlBody, textBo
             mailboxIds: {
               [sentMailbox.id]: true,
             },
-            keywords: {
-              $draft: true,
-            },
             from: [{ email: jmapConfig.username }],
             to: [{ email: to }],
             subject: subject,
-            htmlBody: [{ partId: 'html', type: 'text/html' }],
-            textBody: [{ partId: 'text', type: 'text/plain' }],
-            attachments: [
-              {
-                blobId: null, // Will be set via bodyValues
-                type: attachment.mimeType || 'application/pdf',
-                name: attachment.filename,
-                disposition: 'attachment',
-              },
-            ],
+            bodyStructure: {
+              type: 'multipart/mixed',
+              subParts: [
+                {
+                  type: 'multipart/alternative',
+                  subParts: [
+                    {
+                      type: 'text/plain',
+                      partId: 'text',
+                    },
+                    {
+                      type: 'text/html',
+                      partId: 'html',
+                    },
+                  ],
+                },
+                {
+                  type: mimeType,
+                  name: attachment.filename,
+                  disposition: 'attachment',
+                  blobId: blobId,
+                },
+              ],
+            },
             bodyValues: {
-              html: {
-                value: htmlBody,
-              },
-              text: {
-                value: textBody,
-              },
+              html: { value: htmlBody },
+              text: { value: textBody },
             },
           },
         },
@@ -212,148 +252,12 @@ const sendEmailWithAttachment = async (jmapConfig, to, subject, htmlBody, textBo
     ],
   ]);
 
-  // Check if we need to upload blob first (for some JMAP servers)
   const createResult = createResponse.methodResponses[0][1];
-
-  if (createResult.notCreated?.draft) {
-    // Try alternative approach - upload blob first, then create email
-    logger.info('Skúšam alternatívny prístup s nahraním prílohy');
-
-    // Upload blob
-    const uploadResponse = await jmapRequest(jmapConfig, [
-      [
-        'Blob/upload',
-        {
-          accountId: jmapConfig.accountId,
-          create: {
-            attachment1: {
-              data: [{ 'data:asBase64': base64Content }],
-              type: attachment.mimeType || 'application/pdf',
-            },
-          },
-        },
-        'blob1',
-      ],
-    ]);
-
-    const blobId = uploadResponse.methodResponses[0][1]?.created?.attachment1?.blobId;
-
-    if (!blobId) {
-      // Try yet another approach - inline base64
-      logger.info('Skúšam inline base64 prílohu');
-
-      const inlineResponse = await jmapRequest(jmapConfig, [
-        [
-          'Email/set',
-          {
-            accountId: jmapConfig.accountId,
-            create: {
-              draft: {
-                mailboxIds: {
-                  [sentMailbox.id]: true,
-                },
-                keywords: {
-                  $draft: true,
-                },
-                from: [{ email: jmapConfig.username }],
-                to: [{ email: to }],
-                subject: subject,
-                bodyStructure: {
-                  type: 'multipart/mixed',
-                  subParts: [
-                    {
-                      type: 'multipart/alternative',
-                      subParts: [
-                        {
-                          type: 'text/plain',
-                          partId: 'text',
-                        },
-                        {
-                          type: 'text/html',
-                          partId: 'html',
-                        },
-                      ],
-                    },
-                    {
-                      type: attachment.mimeType || 'application/pdf',
-                      name: attachment.filename,
-                      disposition: 'attachment',
-                      partId: 'attachment',
-                    },
-                  ],
-                },
-                bodyValues: {
-                  html: { value: htmlBody },
-                  text: { value: textBody },
-                  attachment: { value: base64Content, isEncodingProblem: false },
-                },
-              },
-            },
-          },
-          'set2',
-        ],
-      ]);
-
-      const inlineResult = inlineResponse.methodResponses[0][1];
-      const createdEmailId = inlineResult.created?.draft?.id;
-
-      if (!createdEmailId) {
-        logger.error('Nepodarilo sa vytvoriť email s prílohou', inlineResult.notCreated?.draft);
-        throw new Error('Nepodarilo sa vytvoriť email s prílohou');
-      }
-
-      // Submit the email
-      return await submitEmail(jmapConfig, createdEmailId);
-    }
-
-    // Create email with uploaded blob
-    const emailWithBlobResponse = await jmapRequest(jmapConfig, [
-      [
-        'Email/set',
-        {
-          accountId: jmapConfig.accountId,
-          create: {
-            draft: {
-              mailboxIds: {
-                [sentMailbox.id]: true,
-              },
-              from: [{ email: jmapConfig.username }],
-              to: [{ email: to }],
-              subject: subject,
-              htmlBody: [{ partId: 'html', type: 'text/html' }],
-              textBody: [{ partId: 'text', type: 'text/plain' }],
-              attachments: [
-                {
-                  blobId: blobId,
-                  type: attachment.mimeType || 'application/pdf',
-                  name: attachment.filename,
-                  disposition: 'attachment',
-                },
-              ],
-              bodyValues: {
-                html: { value: htmlBody },
-                text: { value: textBody },
-              },
-            },
-          },
-        },
-        'set3',
-      ],
-    ]);
-
-    const createdEmailId = emailWithBlobResponse.methodResponses[0][1].created?.draft?.id;
-
-    if (!createdEmailId) {
-      throw new Error('Nepodarilo sa vytvoriť email s prílohou');
-    }
-
-    return await submitEmail(jmapConfig, createdEmailId);
-  }
-
   const createdEmailId = createResult.created?.draft?.id;
 
   if (!createdEmailId) {
-    throw new Error('Nepodarilo sa vytvoriť email');
+    logger.error('Nepodarilo sa vytvoriť email s prílohou', createResult.notCreated?.draft);
+    throw new Error('Nepodarilo sa vytvoriť email s prílohou');
   }
 
   return await submitEmail(jmapConfig, createdEmailId);