this code is for one [ my ] email id only

replace my email id, smtp, etc…

code is available also @_ https://lists.gnu.org/archive/html/help-gnu-emacs/2023-09/msg00142.html

~ /.emacs

;; pop3

(require 'smtpmail)
(require 'rmail)

(setq user-mail-address "jindam@list.ru") 
(setq user-full-name "జిందం వాఐి") 
(setq smtpmail-smtp-user "jindam@list.ru"    
          smtpmail-smtp-server "smtp.mail.ru" 
           smtpmail-smtp-service 465 
           smtpmail-stream-type 'ssl)

(setq
     rmail-preserve-inbox 1                     ; Don't delete mail from server
     rmail-mail-new-frame 1                     ; Compose in a full frame
     rmail-delete-after-output 1                ; Delete original mail after copying
     rmail-mime-prefer-html nil                 ; Prefer plaintext when possible
     rmail-file-name   "~/mail/inbox"           ; The path to our inbox file
     rmail-secondary-file-directory "~/mail"    ; The path to our other mbox files
     message-default-headers "Fcc: ~/mail/sent") ; Copy sent mail to the "sent" file

;; Debug
(setq smtpmail-debug-info t)
(setq smtpmail-debug-verb t)

;; html
(setq
 shr-use-fonts nil  ; Don't load fancy fonts
 shr-indentation 2  ; A left-margin of 2 columns
 shr-use-colors nil ; Don't load special colors
 shr-width 32       ; Fix width to 70 columns
 shr-bullet "• ")   ; A bullet character for <li> elements

;; tls
(setq rmail-movemail-flags "--tls")

;; Use Mail mode to compose messages (default)
(setq mail-user-agent 'sendmail-user-agent)

;; If you're using rmail
(setq read-mail-command 'rmail)

;;(setq rmail-primary-inbox-list
&nbsp; ;;&nbsp; &nbsp; (cons (concat "pop3://"
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ;;&nbsp; &nbsp; &nbsp; "jindam@list.ru"
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;;;&nbsp; &nbsp; &nbsp; "@pop.mail.ru") nil))

(setq
;; The mail URL, specifying a remote mail account
;; (Omit this to read from /var/mail/user)
rmail-primary-inbox-list
  '("pops://jindam@list.ru@pop.mail.ru"))
```</li>