Hi Muhammad,
1. Go to t code CRMC_UI_NBLINKS
2. CLick on "Define Logical Links" and create a Z copy of loglinkID "SLS-EMI-SR".
3. CLick on "Define Work Centers" and create a Z copy of "SLS-EMail" work center. Here assign the logical link id created in step 2.
4. Go to Define navigation bar profi bar profiles and select your nav bar profile and click on "Assign Wor Centers to Navigation Bar Profiles". Create a new entry with the Z work center created in step 4 and save.
As a alternate you can directly assign the standard work center "SLS-EMAIL" to your navigation profile.
Thanks,
APoorv DHawan