Neither the examiner nor the applicant should use email without having previously agreed to this, e.g. during a telephone consultation. There must be mutual agreement between the examiner and the applicant to such use. Furthermore, the mere fact that an email address is indicated on a letter head does not mean that the examiner can simply use such an email address for file-related topics.
If, on the other hand, an examiner receives an email from an applicant concerning procedural requests or addressing any substantive issues without previous agreement, such an email cannot simply be ignored but must be dealt with, ensuring that the content is put in the official file (see also T 599/06); it is recommended that such an email be replied to with the clear message that email is not an official means of communication and that any requests should be filed by permitted means (see A‑II, 1.1; A‑II, 1.2 and A‑II, 1.3). See however C‑VII, 2.6, and E‑III, 11.3.2, for the use of email during an interview or oral proceedings held as a video-conference.