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Sectors & Eco systems

Group solutions from Deutsche Telekom

      • You are using a centralized certificate in your company.

        To send encrypted e-mails using S/MIME you should ask your internal technical contact person to contact us ( so that we can implement your certificate.

      • The e-mail sender may have knowingly or unknowingly (i.e., mail profile preferences) sent the e-mail as confidential.

        All e-mails marked as “confidential”, which are sent to external communication partners, are automatically encrypted. The e-mail sender needs to remove the ”confidential” flag in Microsoft Outlook.

      • The reason is the format of the sent e-mail. The e-mail to be encrypted cannot be sent in RTF format (see Microsoft Knowledge Base:

      • Attachments to a PDF document will only be visible in Adobe Acrobat Reader once you have clicked the paper clip icon at the bottom left of the file.

      • Adobe Acrobat Reader versions 7, 8 and 9 cannot open attachments containing ZIP files. The reason is a restrictive Adobe policy setting in the Windows registry, due to the fact that ZIP files may contain malware. You can change this setting in the registry.

        To do so, follow the steps outlined below. Adobe Acrobat Reader 7.x: Do the following to edit the Windows registry and to change the security settings for handling file attachments in Adobe Acrobat Reader 7:

        1. Choose Start > Run.
        2. Type “regedit” into the “Open” box and click OK to start the Windows registry editor.
        3. Navigate to the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\AcrobatReader\[versionnumber]\FeatureLockdown\cDefaultLaunchAttachmentPerms
        4. Double-click the following value: sBuiltInPermList
        5. Scroll further down the page, if necessary, to locate the file type extension (.zip). The file type extension displays in the right-hand column of the values list.
        6. Change the number directly after the file type extension to 1. .zip:1 For more information, please see: Adobe Acrobat Reader 8.x, 9.x: The steps necessary for modification are similar to those for Adobe Acrobat Reader 7.x. The only thing that is different here is the location of the registry key in step 3: HKEY_LOCAL_MACHINE\software\policies\adobe\acrobatreader\[version]\FeatureLockDown\cDefaultLaunchAttachmentPerms
      • (1) You need to register with the WebMail service and subsequently upload your certificate that has been approved for encryption. Following this, all e-mails addressed to you will be delivered in encrypted form.

        (2) The certificate you used for signing the registration e-mail contains another e-mail address than the one you are using in your replies. Please use the WebMail service or encrypted PDF delivery.

      • Please contact our support at and they will resend your registration e-mail.

      • At the moment, this error sometimes occurs when the website is accessed from abroad. Please use this link:

      • WebMail service e-mail accounts have a 10MB size limit. Please change your user type in WebMail to PDF or S/MIME and/or PGP (don't forget to upload the respective certificates).

      • Please contact our support at

      • Registering at and using the E-Mail Encryption Gateway is free of charge for you.