Raju, I remembered Onelook's resource when I re-read your opening post this morning. Not wanting to make another 100+ line post, I've eliminated all the ones I know aren't it. If you want the whole list, go to
http://www.onelook.com/?w=*&loc=revfp2&clue=obsessive+desire+of+reading+others'+mails

Words and phrases matching your pattern:
(We're restricting the list to terms we think are related to obsessive desire of reading others' mails, and sorting by relatedness.)

5. fetish
6. phaneromania
7. bibliomania
8. ricky gervais
9. egomania
19. trichotillomania
23. ahnentafel
24. rabbenu gershom
33. mythoclast
34. circumpunct
35. metaphysics of presence
36. dean kamen
37. crapflooding
38. onomastic
39. florence foster jenkins
40. voyeur
41. peter handke
67. echopraxia
69. voyeurism
70. confelicitous
71. eavesdrop
73. epicaricacy
74. grinch
78. arithmomania
79. bugbear
80. coprolalia
82. ethnomania
83. micromanage
84. neurosis
85. obsess
86. oikofugic
87. quantophrenia
92. mail fraud